Showing papers by "University of Hawaii at Manoa published in 1997"

An Equatorial Ocean Recharge Paradigm for ENSO. Part I: Conceptual Model

Abstract: A new conceptual model for ENSO has been constructed based upon the positive feedback of tropical ocean‐ atmosphere interaction proposed by Bjerknes as the growth mechanism and the recharge‐discharge of the equatorial heat content as the phase-transition mechanism suggested by Cane and Zebiak and by Wyrtki. This model combines SST dynamics and ocean adjustment dynamics into a coupled basinwide recharge oscillator that relies on the nonequilibrium between the zonal mean equatorial thermocline depth and wind stress. Over a wide range of the relative coupling coefficient, this recharge oscillator can be either self-excited or stochastically sustained. Its period is robust in the range of 3‐5 years. This recharge oscillator model clearly depicts the slow physics of ENSO and also embodies the delayed oscillator (Schopf and Suarez; Battisti and Hirst) without requiring an explicit wave delay. It can also be viewed as a mixed SST‐ocean dynamics oscillator due to the fact that it arises from the merging of two uncoupled modes, a decaying SST mode and a basinwide ocean adjustment mode, through the tropical ocean‐atmosphere coupling. The basic characteristics of this recharge oscillator, including the relationship between the equatorial western Pacific thermocline depth and the eastern Pacific SST anomalies, are in agreement with those of ENSO variability in the observations and simulations with the Zebiak‐Cane model.

The centers of early-type galaxies with HST. IV. Central parameter relations

Abstract: We analyze Hubble Space Telescope surface-brightness profiles of 61 elliptical galaxies and spiral bulges (hot galaxies). Luminous hot galaxies have cuspy cores with steep outer power-law profiles that break at r ~ r_b to shallow inner profiles with logslope less than 0.3. Faint hot galaxies show steep, largely featureless power-law profiles at all radii and lack cores. The centers of power-law galaxies are up to 1000 times denser in mass and luminosity than the cores of large galaxies at a limiting radius of 10 pc. At intermediate magnitudes (-22.0 < M_V < -20.5), core and power-law galaxies coexist, and there is a range in r_b at a given luminosity of at least two orders of magnitude. Central properties correlate with global rotation and shape: core galaxies tend to be boxy and slowly rotating, whereas power-law galaxies tend to be disky and rapidly rotating. The dense power-law centers of disky, rotating galaxies are consistent with their formation in gas-rich mergers. The parallel proposition that cores are simply the by-products of gas-free stellar mergers is less compelling. For example, core galaxies accrete small, dense, gas-free galaxies at a rate sufficient to fill in low-density cores if the satellites survived and sank to the center. An alternative model for core formation involves the orbital decay of massive black holes (BHs): the BH may heat and eject stars from the center, eroding a power law if any exists and scouring out a core. An average BH mass per spheroid of 0.002 times the stellar mass yields reasonably good agreement with the masses and radii of observed cores and in addition is consistent with the energetics of AGNs and kinematic detections of BHs in nearby galaxies.

An Equatorial Ocean Recharge Paradigm for ENSO. Part II: A Stripped-Down Coupled Model

Abstract: The conceptual recharge oscillator model intuitively established in Part I is derived from a dynamical framework of a Cane–Zebiak type model for tropical ocean–atmosphere interaction. A two-strip approximation to the equatorial ocean dynamics and one-strip approximation to the SST dynamics are employed to obtain a stripped-down coupled model that captures the main physics of the Cane–Zebiak type model. It is shown that the conceptual recharge oscillator model can be obtained from the stripped-down coupled model with a two-box approximation in the zonal direction or a low-frequency approximation to filter out high-frequency modes. Linear solutions of the stripped-down model are analytically solved and the dependence of coupled modes on various model parameters is delineated. In different parameter regimes, the stripped-down coupled model describes a coupled-wave mode and a mixed SST–ocean-dynamics mode that results from the merger of a nonoscillatory ocean adjustment mode with an SST mode. These t...

The Emotional Contagion Scale: A Measure of Individual Differences

Abstract: Three studies (N = 1988) describe the development and validation of the Emotional Contagion (EC) Scale, a 15-item unidimensional measure of susceptibility to others' emotions resulting from afferent feedback generated by mimicry. Study 1 assesses the EC Scale's reliability (Cronbach's α = .90). Study 2 finds susceptibility (a) positively related to reactivity, emotionality, sensitivity to others, social functioning, self-esteem, and more associated with emotional than cognitive modes of empathy, (b) negatively related to alienation, self-assertiveness, and emotional stability and, (c) unrelated to masculinity and approval motivation. Study 3, an experiment, finds that EC Scale scores reliably predict biases in participants' evaluations and are correlated with a measure of responsiveness to afferent feedback and self-reports of emotional experience following exposure to emotional expressions.

Iron and grazing constraints on primary production in the central equatorial Pacific: An EqPac synthesis

Abstract: Recent studies in the central equatorial Pacific allow a comprehensive assessment of phytoplankton regulation in a high-nutrient, low-chlorophyll (HNLC) ecosystem. Elemental iron enters the euphotic zone principally via upwelling and is present at concentrations (530 PM) well below the estimated half-saturation constant (120 PM) for the large cells that bloom with iron enrichment. In addition, the meridional trend in quantum yield of photosynthesis suggests that even the dominant small phytoplankton are held below their physiological potential by iron deficiency. Grazing by microzooplankton dominates phytoplankton losses, accounting for virtually all of the measured phytoplankton production during El Nina conditions and -66% during normal upwelling conditions, with mesozooplankton grazing and lateral advection closing the balance. Nitrate uptake is strongly correlated with the pigment biomass of diatoms, which increase in relative abundance during normal upwelling conditions. Nonetheless, the f-ratio remains low (0.07-0.12) under all conditions. Iron budgets are consistent with the notions that new production is determined by the rate of new iron input to the system while total production depends on efficient iron recycling by grazers. Although the limiting substrates differ, the interactions of resource limitation and grazing in HNLC regions are conceptually similar to the generally accepted view for oligotrophic subtropical regions. In both systems, small dominant phytoplankton grow at rapid, but usually less than physiologically maximal, rates; they are cropped to low stable abundances by microzooplankton; and their sustained high rates of growth depend on the remineralized by-products of grazing.

Sex Reassignment at Birth: Long-term Review and Clinical Implications

Abstract: This article is a long-term follow-up to a classic case reported in pediatric, psychiatric, and sexological literature. The penis of an XY individual was accidentally ablated and he was subsequently raised as a female. Initially this individual was described as developing into a normally functioning female. The individual, however, was later found to reject this sex of rearing, switched at puberty to living as a male, and has successfully lived as such from that time to the present. The standard in instances of extensive penile damage to infants is to recommend rearing the male as a female. Subsequent cases should, however, be managed in light of this new evidence. Arch Pediatr Adolesc Med. 1997;151:298-304

Validity problems comparing values across cultures and possible solutions.

Abstract: The authors argue that commonly used ranking and rating methods of value surveys may have low validity in cross-cultura l value comparisons because participants' reports about values can be affected by factors such as cultural differences in the meaning of particular value terms as well as the possibility that some value judgments are based on social comparison or deprivation rather than on any "direct reading" of personal preferences. Four different value survey methods—ranking, rating, attitude scale, and behavioral scenario methods—were compared. It was found that ranking and rating methods of assessing differences between Chinese and Americans had low convergence with each other and with the criterion of cultural experts' independent judgments. Attitude questions had slight and nonsignificant convergence with the expert judgment criterion. A scenario method of value assessment, however, yielded reasonable criterion validity.

Partner Selection and Venturing Success: The Case of Joint Ventures with Firms in the People's Republic of China

Abstract: It has been hypothesized in the international joint venture IJV literature that partner selection affects interpartner “fit” which in turn influences a synergistic effect on IJV performance. This study investigates the relationship between IJV success and the strategic and organizational traits of local partners. We address this issue in the context of an emerging economy P.R. China. Newly emerging economies have in recent years become major hosts of direct investment by multinational corporations MNCs because these rapidly expanding economies, characterized by an exploding demand previously stifled by ideologically-based government intervention, provide tremendous opportunities which MNCs can preempt. MNCs in such economies, however, face the challenges of structural reform, weak market structure, poorly specified property rights, and institutional uncertainty. Right local partners can help MNCs boost market expansion, obtain insightful information, mitigate operational risks, and provide country-specific knowledge. The analysis of the data obtained from China suggests that both strategic and organizational traits of local partners are significantly associated with some individual dimensions of IJV performance. Among strategic traits, absorptive capacity, product relatedness, and market power are favorable to IJVs' market and financial outcomes. Market power and experience significantly reduce IJVs' operational uncertainties. Of organizational traits, international experience and organizational collaboration are important for IJVs' not only profitability and stability but also local market expansion and export growth. Organizational form and size influence IJVs' local market performance. The findings provided by this study can help MNCs determine what criteria they should use in opting for local partners and what criteria are vital to their goal accomplishment. Those investors seeking local market expansion should select those local partners that have rich market experience, superior market position, high absorptive capacity, and related product diversification with the IJVs. Those seeking profitability and stability should select local firms that have superior international experience, longer organizational collaboration, and greater market power. While MNCs should use appropriate strategic and organizational criteria to select local partners, the host government or local firms can try to make these traits available to attract more stable and profitable foreign direct investment.

Does guanxi influence firm performance

Abstract: It is widely acknowledged that guanxi constitutes a key strategic factor affecting firm performance in the greater China area However, very little empirical research on the issue has been done in the literature In this study we explore the systematic linkage between guanxi and firm performance from a business strategy perspective The evidence shows that guanxi-based business variables have a profound and positive impact on firm efficiency and growth

Management of Intersexuality: Guidelines for Dealing With Persons With Ambiguous Genitalia

Abstract: Following the publication of our article about a classic case of sex reassignment,1the media attention was rapid and widespread,2-4as was the reaction of many clinicians. Some wanted to comment or ask questions, but many contacted us directly or indirectly, asking for specific guidelines on how to manage cases of traumatized or ambiguous genitalia.5 Below we offer our suggestions. We first, however, add this caveat: these recommendations are based on our experiences, the input of some trusted colleagues, the comments of intersexed persons of various origins, and the best interpretation of our reading of the literature. Some of these suggestions are contrary to today's common management procedures. We believe, however, that many of those procedures should be modified. These guidelines are not offered lightly. We anticipate that time and experience will dictate that some aspects be changed and such revisions will improve the next set of

One gene in diamondback moth confers resistance to four Bacillus thuringiensis toxins.

Abstract: Environmentally benign insecticides derived from the soil bacterium Bacillus thuringiensis (Bt) are the most widely used biopesticides, but their success will be short-lived if pests quickly adapt to them. The risk of evolution of resistance by pests has increased, because transgenic crops producing insecticidal proteins from Bt are being grown commercially. Efforts to delay resistance with two or more Bt toxins assume that independent mutations are required to counter each toxin. Moreover, it generally is assumed that resistance alleles are rare in susceptible populations. We tested these assumptions by conducting single-pair crosses with diamondback moth (Plutella xylostella), the first insect known to have evolved resistance to Bt in open field populations. An autosomal recessive gene conferred extremely high resistance to four Bt toxins (Cry1Aa, Cry1Ab, Cry1Ac, and Cry1F). The finding that 21% of the individuals from a susceptible strain were heterozygous for the multiple-toxin resistance gene implies that the resistance allele frequency was 10 times higher than the most widely cited estimate of the upper limit for the initial frequency of resistance alleles in susceptible populations. These findings suggest that pests may evolve resistance to some groups of toxins much faster than previously expected.

Constraints on the role of impact heating and melting in asteroids

Abstract: (Received 1996 August 30; accepted in revised form 1997 January 30) Abstract-Imaging of asteroids Gaspra and Ida and laboratory studies of asteroidal meteorites show that im- pacts undoubtedly played an important role in the histories of asteroids and resulted in shock metamorphism and the formation of breccias and melt rocks. However, in recent years, impact has also been called upon by numerous authors as the heat source for some of the major geological processes that took place on asteroids, such as global thermal metamorphism of chondrite parent bodies and a variety of melting and igneous events. The latter were proposed to explain the origin of ureilites, aubrites, mesosiderites, the Eagle Station pallasites, acapulcoites, lodranites, and the IAB, IIICD, and IIE irons. We considered fundamental observations from terrestrial impact craters, combined with results from laboratory shock experiments and theoretical consider- ations, to evaluate the efficiency of impact heating and melting of asteroids. Studies of terrestrial impact craters and relevant shock experiments suggest that impact heating of aster- oids will produce two types of impact melts: (1) large-scale whole rock melts (total melts, not partial melts) at high shock pressure and (2) localized melts formed at the scale of the mineral constituents (mineral specific or grain boundary melting) at intermediate shock pressures. The localized melts form minuscule amounts of melt that quench and solidify in sifu, thus preventing them from pooling into larger melt bodies. Partial melting as defined in petrology has not been observed in natural and experimental shock metamor- phism and is thermodynamically impossible in a shock wave-induced transient compression of rocks. The total impact melts produced represent a minuscule portion of the displaced rock volume of the parent crater. Internal differentiation by fractional crystallization is absent in impact melt sheets of craters of sizes that can be tolerated by asteroids, and impact melt rocks are usually clast-laden. Thermal metamorphism of country rocks by impact is extremely minor. Experimental and theoretical considerations suggest that (1) single dis- ruptive impacts cannot raise the average global temperature of strength- or gravity-dominated asteroids by more than a few degrees; (2) cumulative global heating of asteroids by multiple impacts is ineffective for asteroids less than a few hundred kilometers in diameter; (3) small crater size, low gravity, and low impact velocity suggest that impact melt volume in single asteroidal impacts is a very small (-0.014.1%) fraction of the total displaced crater volume; (4) total impact melt volume formed during the typical lifetime of an asteroid is a small fraction (<0.001) of the volume of impact-generated debris; and (5) much of the impact melt generated on asteroidal targets is ejected from craters with velocities greater than escape velocity and, thus, not retained on the asteroid. The inescapable conclusion from these observations and calculations is that impacts cannot have been the heat source for the origin of the meteorite types listed above, and we must turn to processes other than impact, such as decay of short-lived radionuclides or electromagnetic induction during an early T-tauri phase of the Sun to explain heating and melting of the parent bodies of these meteorites.

Reputation, Image, Prestige, and Goodwill: An Interdisciplinary Approach to Organizational Standing

Abstract: Reputation, image, prestige, and goodwill are concepts used by different disciplines, e.g., economics, marketing, sociology, and accounting, to denote the general standing of organizations among their counterparts. In this paper, the various concepts are reviewed and compared in terms of semantics, organizational cost, determinants, and implications, among others. An interdisciplinary, multiconstituency framework of organizational standing is developed, and research propositions are delineated.

Frequency and characteristics of silent dementia among elderly Japanese-American men. The Honolulu-Asia Aging Study.

Abstract: Objective. —To determine the frequency of unrecognized dementia in a group of men found to have dementia by population survey, and to identify factors associated with the failure of a family informant to recognize significant memory impairment. Design and Setting. —The Honolulu-Asia Aging Study, a population-based study of dementia among elderly Japanese-American men living on the island of Oahu, Hawaii. Data for this study were from the dementia prevalence survey, 1991-1993. Study Participants. —A total of 191 noninstitutionalized men with dementia who had a reliable family informant. Main Outcome Measures. —Failure of family informants to recognize a problem with thinking or memory in subjects with dementia. Results. —A total of 21% of family informants failed to recognize a problem with memory among subjects subsequently found to have dementia. Among subjects with very mild dementia, 52% of family informants failed to recognize a significant memory problem compared with 13% among more severely demented subjects. Of the subjects with dementia whose family informants did recognize a memory problem, 53% failed to receive a medical evaluation for this problem. For all family informants, increasing age, fewer years of education, less severe dementia, fewer behavioral complications, fewer functional disabilities, and better performance on certain tests of memory and language were significantly associated with the family informant's failure to recognize a problem with memory. When the family informants were wives living with husbands, less severe dementia, fewer behavioral complications, fewer functionaldisabilities, and intact remote memory were associated with unrecognized dementia. Conclusions. —Unrecognized dementia was common in our population, especially among mild cases. Cognitive screening programs for the elderly and public education policies designed to increase awareness of early signs of dementia are needed if interventions for individuals with potentially treatable dementias are to be implemented.

Gender- and grade-level differences in science interest and participation

Abstract: A cluster of three public schools was studied in an effort to assess students' attitudes toward and participation in science, and how they might vary by gender and grade. Two to three classes at each grade level from K–12 were surveyed to assess and compare attitudes toward science, extent of prior science-related experiences, and perceptions of science and scientists; each class also was observed to determine the relative numbers of teacher–student dyadic interactions related to each gender, as well as the proportions of girls and boys actively versus passively participating in laboratory activities. Overall, girls and boys expressed similar opinions on all survey scales, but girls were less likely to view science as a male-stereotyped field; younger students expressed more positive attitudes toward science than did older students. Girls also participated actively in science class: they initiated as many teacher interactions as did boys, but did not receive as much teacher attention; from elementary school to the early secondary years they also were as likely as boys to manipulate science equipment as to record data. © 1997 John Wiley & Sons, Inc.

A Theory of Interdecadal Climate Variability of the North Pacific Ocean–Atmosphere System*

Abstract: A linear coupled model for the atmosphere–upper-ocean system is proposed to highlight the mechanisms of decadal to interdecadal climate variability in the North Pacific. In this model, wind stress anomalies over the North Pacific are related to anomalies in the meridional temperature gradient of the upper ocean. The latter depends upon air–sea thermodynamical feedbacks and meridional heat transport by upper-ocean currents. Slow adjustment of the oceanic gyre circulation to the change in wind stress is accomplished by the forced baroclinic oceanic Rossby waves, which carry out the meridional heat transport. Uncoupled ocean dynamic adjustment can produce a weak decadal to interdecadal peak in the power spectrum of the meridional transport under temporal white noise wind stress forcing with organized spatial structure. Coupled dynamics produce a basin-scale interdecadal oscillatory mode. This mode arises from the dynamic coupling and the memory of the system, residing in the slow gyre circulation ad...

Inheritance of Resistance to the Bacillus thuringiensis Toxin Cry1C in the Diamondback Moth

Abstract: Laboratory selection increased resistance to the Bacillus thuringiensis toxin Cry1C in a strain of diamondback moth (Plutella xylostella). The selected strain was derived from a field population that had evolved high levels of resistance to Bacillus thuringiensis subsp. kurstaki and moderate resistance to Cry1C. Relative to the responses of a susceptible strain of diamondback moth, the resistance to Cry1C of the selected strain increased to 62-fold after six generations of selection. The realized heritability of resistance was 0.10. Analysis of F(inf1) hybrid progeny from reciprocal crosses between the selected strain and a susceptible strain showed that resistance to Cry1C was autosomally inherited. The dominance of resistance to Cry1C depended on the concentration; inheritance was increasingly dominant as the concentration decreased. Responses of progeny from single-pair families showed that resistance to Cry1C and resistance to Cry1Ab were inherited independently, which enhances opportunities for managing resistance. However, compared with projections based on previously reported recessive inheritance of resistance to Cry1A toxins, the potentially dominant inheritance of resistance to Cry1C observed here could accelerate evolution of resistance.

Genetic algorithms for adaptive motion planning of an autonomous mobile robot

Abstract: This paper proposes genetic algorithms (GAs) for path planning and trajectory planning of an autonomous mobile robot. Our GA-based approach has an advantage of adaptivity such that the GAs work even if an environment is time-varying or unknown. Therefore, it is suitable for both off-line and online motion planning. We first present a GA for path planning in a 2D terrain. Simulation results on the performance and adaptivity of the GA on randomly generated terrains are presented. Then, we discuss extensions of the GA for solving both path planning and trajectory planning simultaneously.

A geometric technique for relocating hotspots and refining absolute plate motions

Abstract: An age-independent, geometric relationship is presented that links hotspots to the seamounts which they produce, and so permits the use of undated seamounts to refine the motion of tectonic plates. This technique has the potential to rigorously assess hotspot fixity and to locate extinct hotspots. The present application of this method points to a recent change in Pacific plate motion, and suggests a relocation of the Louisville hotspot to the Hollister ridge, south of the Eltanin fracture zone.

Control of transpiration from the upper canopy of a tropical forest: the role of stomatal, boundary layer and hydraulic architecture components

Abstract: Concurrent, independent measurements of stomatal conductance (gs), transpiration (E) and microenvironmental variables were used to characterize control of crown transpiration in four tree species growing in a moist, lowland tropical forest. Access to the upper forest canopy was provided by a construction crane equipped with a gondola. Estimates of boundary layer conductance (gb) obtained with two independent methods permitted control of E to be partitioned quantitatively between gs and gb using a dimensionless decoupling coefficient (Ω) ranging from zero to 1. A combination of high gs (c. 300–600 mmol m−2 s−1) and low wind speed, and therefore relatively low gb (c. 100–800 mmol m−2 s−1), strongly decoupled E from control by stomata in all four species (Ω= 0.7–0.9). Photosynthetic water-use efficiency was predicted to increase rather than decrease with increasing gs because gb was relatively low and internal conductance to CO2 transfer was relatively high. Responses of gs to humidity were apparent only when the leaf surface, and not the bulk air, was used as the reference point for determination of external vapour pressure. However, independent measurements of crown conductance (gc), a total vapour phase conductance that included stomatal and boundary layer components, revealed a clear decline in gc with increasing leaf-to-bulk air vapour pressure difference (Va because the external reference points for determination of gc and Va were compatible. The relationships between gc and Vc and between gs and Vs appeared to be distinct for each species. However, when gs and gc were normalized by the branch-specific ratio of leaf area to sapwood area (LA/SA), a morphological index of potential transpirational demand relative to water transport capacity, a common relationship between conductance and evaporative demand for all four species emerged. Taken together, these results implied that, at a given combination of LA/SA and evaporative demand scaled to the appropriate reference point, the vapour phase conductance and therefore transpiration rates on a leaf area basis were identical in all four contrasting species studied.

Multiwavelength optical networks with limited wavelength conversion

Abstract: This paper proposes optical wavelength division multiplexed (WDM) networks with limited wavelength conversion that can efficiently support lightpaths (connections) between nodes. Each lightpath follows a route in the network and must be assigned a channel along each link in its route. The load /spl lambda//sub max/ of a set of lightpath requests is the maximum over all links of the number of lightpaths that use the link. At least /spl lambda//sub max/ wavelengths will be needed to assign channels to the lightpaths. If the network has full wavelength conversion capabilities then /spl lambda//sub max/ wavelengths are sufficient to perform the channel assignment. We propose ring networks with a fixed wavelength conversion capability within the nodes that can support all lightpath request sets with load /spl lambda//sub max/ at most W-1, where W is the number of wavelengths in each link. We also propose ring networks with selective pairwise wavelength conversion capability within the nodes that can support all lightpath request sets with load /spl lambda//sub max/ at most W. We also propose a star network with fixed wavelength conversion capability at its hub node that can support all lightpath request sets with load /spl lambda//sub max/ at most W. We extend this result to tree networks and networks with arbitrary topologies. These results show that significant improvements in traffic-carrying capacity can be obtained in WDM network by providing a very limited wavelength conversion capability within the network.

Productive Efficiency of the Swine Industry in Hawaii: Stochastic Frontier vs. Data Envelopment Analysis

Abstract: Improving productive efficiency is an increasingly important determinant of the future of the swine industry in Hawaii. This paper examines the productive efficiency of a sample of swine producers in Hawaii by estimating a stochastic frontier production function and the constant returns to scale (CRS) and variable returns to scale (VRS) output-oriented DEA models. The technical efficiency estimates obtained from the two frontier techniques are compared. The scale properties are also examined under the two approaches. The industry's potential for increasing production through improved efficiency is also discussed.

Origin of fayalitic olivine rims and lath‐shaped matrix olivine in the CV3 chondrite Allende and its dark inclusions

Abstract: — We have studied an Allende dark inclusion by optical microscopy, scanning electron microscopy, electron microprobe analysis and transmission electron microscopy. The inclusion consists of chondrules, isolated olivines and matrix, which, as in the Allende host, is mainly composed of 5–20 μm long lath-shaped fayalitic grains with a narrow compositional range (Fa42 ± 2) and nepheline. Olivine phenocrysts in chondrules and isolated olivine grains show various degrees of replacement by 5–10 μm wide fayalitic rims (Fa39 ± 2) and 100–1000 μm wide translucent zones, which consist of 5–20 μm long lath-shaped fayalitic grains (Fa41 ± 1) intergrown with nepheline. These fayalitic olivines, like those in the matrix of the dark inclusion, contain 10–20 nm sized inclusions of chromite, hercynite, and Fe-Ni sulfides. The fayalitic rims around remnant olivines are texturally and compositionally identical to those in Allende host, suggesting that they have similar origins. Chondrules are surrounded by opaque rims consisting of tiny lath-shaped fayalitic olivines (<1–3 μm long) intergrown with nepheline. As in the Allende host, fayalitic olivine veins may crosscut altered chondrules, fine-grained chondrule rims and extend into the matrix, indicating that alteration occurred after accretion. We infer that fayalitic olivine rims and lath-shaped fayalites in Allende and its dark inclusions formed from phyllosilicate intermediate phases. This explanation accounts for (1) the similarity of the replacement textures observed in the dark inclusion and Allende host to aqueous alteration textures in CM chondrites; (2) the anomalously high abundances of Al and Cr and the presence of tiny inclusions of spinels and sulfides in fayalitic olivines in Allende and Allende dark inclusions; (3) abundant voids and defects in lath-shaped fayalites in the Allende dark inclusion, which may be analogous to those in partly dehydrated phyllosilicates in metamorphosed CM/CI chondrites. We conclude that the matrix and chondrule rims in Allende were largely converted to phyllosilicates and then completely dehydrated. The Allende dark inclusions experienced diverse degrees of aqueous/hydrothermal alteration prior to complete dehydration. The absence of low-Ca pyroxene in the dark inclusion and its significant replacement by fayalitic olivine in Allende is consistent with the lower resistance of low-Ca pyroxene to aqueous alteration relative to forsteritic olivine. Hydro-thermal processing of Allende probably also accounts for the low abundance of planetary noble gases and interstellar grains, and the formation of nepheline, sodalite, salite-hedenbergite pyroxenes, wollastonite, kirschsteinite and andradite in chondrules and Ca,Al-rich inclusions.