Showing papers by "University of New Hampshire published in 1980"

South-seeking magnetotactic bacteria in the Southern Hemisphere

Abstract: Several species of aquatic bacteria which orient in the Earth's magnetic field and swim along magnetic field lines in a preferred direction (magnetotaxis) have been observed in marine and freshwater sediments of the Northern Hemisphere1,2. Their orientation is due to one or more intracytoplasmic chains of single-domain magnetite particles3. These linearly arranged particles impart a net magnetic dipole moment to the bacterium, parallel to the axis of motility. Northern Hemisphere magnetotactic bacteria with unidirectional motility swim consistently in the direction of the magnetic field, that is, to the geomagnetic North1,2,4. This implies that their magnetic dipole is systematically orientated with the North-seeking pole forward. The magnetic polarity can be reversed by single, magnetic pulses of high field strength (1–2 µs, 300–600 G), and these bacteria then swim along magnetic field lines to the South5. Due to the inclination of the Earth's magnetic field, magnetotactic bacteria which swim to the North in the Northern Hemisphere are directed downward at an angle increasing with latitude. It has been suggested that this downward-directed motion confers a biological advantage by guiding the bacteria, when dislodged, back to the sediments1. On the basis of this hypothesis, magnetotactic bacteria of the Southern Hemisphere would be expected to swim to the South to reach the bottom. We report here several morphological types of magnetotactic bacteria present in sediments of the Southern Hemisphere. These bacteria indeed swim consistently to the South, hence downward along the Earth's inclined magnetic field lines, as hypothesized. As revealed by electron microscopy, they contain internal chains of electron-opaque particles similar to those observed in magnetotactic bacteria from the Northern Hemisphere. Like their Northern Hemisphere counterparts, their magnetic polarity can be permanently reversed and they cannot be demagnetized. We also report on Northern Hemisphere magnetotactic bacteria incubated in Southern Hemisphere magnetic conditions, confirming the biological relevance of downward directed motility.

Sex Among Siblings: A Survey on Prevalence, Variety, and Effects

Abstract: In a survey of 796 undergraduates at six New England colleges and universities, 15% of the females and 10% of the males reported some type of sexual experience involving a sibling. Fondling and touching of the genitals were the most common activities in all age categories. One-fourth of the experiences could be described as exploitative either because force was used or because there was a large age disparity between the partners. Reactions to the experiences were equally divided among those who considered them positive and those who considered them negative. Females were more likely than males to have been exploited and feel badly about it. Few participants of either sex ever told anyone. The research finds evidence that such experience may have long-term effects on sexual development. Females who report sibling sexual experiences, both positive and negative, have substantially higher levels of current sexual activity. Their level of sexual self-esteem may also have been affected, but more selectively. Those with positive sibling experiences after age 9 have more sexual self-esteem. However, experiences with much older siblings taking place before age 9 are associated with generally lower levels of self-esteem and no increase in current sexual activity.

Social stress and marital violence in a national sample of american families

Abstract: The National Family Violence Surveys suggest that the family is the most violent institution, group, or setting that a typical citizen is likely to encounter. Assault was measured by the severe violence index of the family Conflict Tactics Scales. Physical punishment provides the society's basic training in violence but, of course, training that applies most directly to behavior in the family. At least some use of physical punishment is just about universal in American society, typically beginning in infancy. The chapter examines one of the several factors that contribute to the explanation: the link between stress and violence. The last set of mediating factors included in the chapter explores the theory that violence will be higher in the absence of a network of personal ties. The usual formulation of that theory assumes that the network will be pro social. That is usually a reasonable assumption. However, a social network can also support antisocial behavior.

Victims and Aggressors in Marital Violence

Abstract: One of the cruel ironies of marriage is that, although husbandwife relationships are largely male-dominant, the use of physical violence seems to be one of the few aspects of marriage which approach equality between spouses. There is irony in this also because, except for the rare instances when a desperate or enraged woman seizes a knife or gun and is effective in using it, the effects of this violence are far from equal. She may cast the first coffee pot, but he generally casts the last and

The gamma ray spectrometer for the Solar Maximum Mission.

Abstract: The paper describes an actively shielded, multicrystal scintillation spectrometer for measurement of the solar gamma ray flux used by the Solar Maximum Mission Gamma Ray Experiment. The instrument provides a 476-channel pulse height spectrum every 16.38 s over the 0.3-9 MeV energy range; the gamma ray spectral analysis can be extended to at least 15 MeV on command. The instrument is designed to measure the intensity, energy, and Doppler shift of narrow gamma ray lines, the intensity of extremely broadened lines, and the photon continuum.

Genetics of allozyme variants in loblolly pine

Abstract: ' 4 . Applications of isozymes in breeding programs also have been demonstrated' 9 ". However, we must understand how isozyme variants are inherited to fully realize their value in genetic investigations. Furthermore, we must look at as many loci as possible if results are to be more representative of the entire genome' 0 . To date, few reports have been published on the inheritance of isozymes in forest trees, and fewer still have involved more than two or three loci ' .1 8.22 . The presence of the haploid (In) megagametophyte tissue in seeds has greatly facilitated isozyme studies in conifers. Each megagametophyte, representing a single meiotic product, has the same genetic constitution as the female gamete. Thus, the Mendelian genetics of allozyme (allelic isozyme) variants can be confirmed without making crosses because allozymes are expected to segregate in 1:1 ratios in the megagametophytes of heterozygous mother trees. In addition, when allozymes are expressed clearly in both embryo and megagametophyte tissues, the male contribution to the embryo' genotype can be separated from that of the female. This unique feature of conifers has proven useful for studying pollen migration 7 and mating systems in forest trees ' ' 6 . In this paper, we describe allozyme variants of 10 enzyme systems occurring in megagametophyte and embryo tissues of loblolly pine (Pinus taeda L.) seeds and provide evidence for their inheritance. Linkage relationships among the loci coding these allozymes are reported elsewhere 2 .

Feedback functions for variable-interval reinforcement

Abstract: On a given variable-interval schedule, the average obtained rate of reinforcement depends on the average rate of responding. An expression for this feedback effect is derived from the assumptions that free-operant responding occurs in bursts with a constant tempo, alternating with periods of engagement in other activities; that the durations of bursts and other activities are exponentially distributed; and that the rates of initiating and terminating bursts are inversely related. The expression provides a satisfactory account of the data of three experiments.

Offender-Victim Relationships in Criminal Homicide Followed by Offender's Suicide, North Carolina, 1972–1977

Abstract: An analysis of 90 cases of criminal homicide followed by suicide in North Carolina, 1972 to 1977. Homicidal victim-offender relationships were investigated in regard to age, sex, race and whether victim and offender were member of the same family, friends, acquaintances, or strangers. These results were compared with victim-offender relationships in 994 criminal homicide cases in North Carolina in which offenders did not commit suicide. Married white males over 30 years were much more involved in homicide-suicide than they were in homicide alone. In these homicide-suicide cases, the victim was usually the spouse. Except for marital status, characteristics of homicide offenders who killed themselves resembled those of suicide-only individuals much more than those of homicide-only offenders. In the homicide-suicide cases, the killing of someone in close relationship to the offender, often a wife, appeared to be part of the evolving process of suicide. This clearly has implications for intervention into marital strife and also for immediate treatment of homicide offenders who kill spouses and other family members.

Seasonal influx and decomposition of autochthonous macrophyte litter in a north temperate estuary

Abstract: An 18-month study was undertaken to determine the seasonal contribution and detrital processing of autochthonous plant litter in the Great Bay Estuary System of New-Hampshire-Maine, USA and adjacent open coast. Four species were studied: the halophytes, Spartina alterniflora Loisel. and Zostera marina L. and the seaweeds, Ascophyllum nodosum (L.) Le Jolis and Fucus vesiculosus L. v. spiralis Farlow. Monthly strand line collections at estuarine and open coastal sites provided information on the seasonal influx of litter derived from each species. Detrital inputs from S. alterniflora and Z. marina were maximal in the spring and summer, respectively. Seaweed litter was abundant (35 to 85% of the total strand line) throughout the year. The seaweeds contributed 1 to 3 times as much detrital material as the vascular plants within the Estuary, and 50 times as much on the open coast. In situ measurements of decomposition, using nylon, mesh bags, were made for each species under several environmental conditions. Seaweeds decomposed 3 to 10 times faster than vascular plant litter under similar conditions. Decomposition rates and changes in the nutrient content of litter were dependent on surrounding environmental conditions. Continual nutrient depletion occurred in litter within the strand line. Nitrogen and phosphorus enrichment were observed under submerged conditions and were attributed to microbial activity and rapid leaching of carbonaceous substrates. A computer simulation model was developed to validate the field data and to predict seasonal detrital carbon input by each species. The significance of autochthonous input is discussed in relation to other detrital sources.

Orientation to Landmarks within the Preferred Habitat by Peromyscus leucopus

Abstract: A field study was conducted in two woodlots to identify the major physical features of the habitat that Peromyscus leucopus uses in short-range orientation and navigation, and to which it is responsive in the process of habitat selection. In one woodlot, landmarks used for short-range orientational and navigational aids were trees, logs (fallen branches and tree trunks), rocks, stone fences, and rock piles. In the other woodlot, trees (particularly those of large diameter) were important but logs and rocks were avoided to some extent. For both woodlots, areas with high densities of woody stems were avoided; logs were not important as refuge sites.

Spermatogenic columns, somatic cells, and the microenvironment of germinal cells in the testes of asteroids

Abstract: Sixty-seven specimens of the common North Atlantic asteroid, Asterias vulgaris, were collected at seasonal intervals over a 2-year period and their testes observed with both light and electron microscopy. In the germinal epithelium, a predictable series of interactions between versatile somatic cells and germinal cells is repeated annually in relation to sequential events in spermatogenesis. For example, massive proliferation and differentiation of spermatogenic cells depend on the elaboration of thousands of spermatogenic columns, which are distinct cellular subdivisions of the germinal epithelium. Each fully developed column is composed of at least one somatic cell surrounded by ≈ 400 germinal cells. Such columns form only after intensive spermatogonial mitosis begins in the germinal epithelium. Single annual periods of spermatogenic proliferation and differentiation are initiated from 1 to 3 months out of phase in different individuals and overlap incompletely. Therefore, it is possible to observe testes that are entirely in the proliferative phase, entirely in the differentiative phase, or in both phases simultaneously. Detailed ultrastructural observations and preliminary autoradiographic data demonstrate that columns maintain their height for a variable period of time as germinal cells are generated near their bases, pass along their lengths, and differentiate near their tips; therefore, simultaneous proliferation and differentiation of more than one generation of germinal cells occur in the same column. Finally, formation of primary spermatocytes ceases basally, (terminating proliferation), and remaining columns degrade completely as germinal cells composing them differentiate or are phagocytized (terminating differentiation and spermatogenesis); resulting spermatozoa ultimately accumulate in the expandable lumen. It is proposed that spermatogenic columns provide the structural basis for organization of the microenvironment of small groups of spermatogenic cells (≈ 400 at a time) during proliferation and differentiation. Preliminary evidence from A. vulgaris and other species also suggests that somatic cells are temporally pluripotent and are variously involved in the formation, structure, and activities of columns, in extensive phagocytosis, and probably in contributing intrinsic (e.g., 1-methyl adenine and steroids) and mediating extrinsic (e.g., gamete shedding substance and nutrients) microenvironmental factors influential during spermatogenesis in asteroids. The prodigious spermatogenic capabilities of asteroids apparently depend on the generation of spermatogenic columns, on the progressive interaction of germinal and somatic cells before, during, and after columns form, and on the predictable effects of microenvironmental factors received and interpreted at the structural level of the spermatogenic column.

The historical foundation of Herbart's mathematization of psychology.

Abstract: Herbart's mathematization of psychology is an important landmark in the history of psychology. The purpose of this article is to describe the general landscape within which this landmark was created and the specific foundation upon which it was erected. Besides Kant's classic statements on the nature of science, the “external” landscape included other landmarks in the historical quest for a mathematical science of man, while the “internal” foundation was composed of four basic concepts which Herbart received primarily from Leibniz, Wolff, and Kant. Herbart's unique contribution was his novel use of this foundation in creating a mathematical psychology.

Oscillations in the reproductive condition of Diaptomus leptopus (Copepoda: Calanoida) and their relation to rates of egg-clutch production.

Abstract: Isolated female D. leptopus oscillate between gravid and nongravid reproductive conditions. When gravid, the oviducts are visible as a pair of dark bands lateral to the digestive tract. Periodically the females revert to a nongravid condition by releasing all the unfertilized oocytes into the environment. The oviducts then remain transparent until they refill with ripe gametes. The characteristics of this gametogenic cycle were defined at 18° C using females cultured under controlled conditions. The average period of the cycle was 4.4 days, with a gravid phase (dark oviducts) of 3.4 days and a nongravid phase (clear oviducts) of 0.9 days. Observations made in situ confirmed the oscillatory nature of the changes in reproductive status. The duration of the nongravid phase was shown to represent the minimal time interval between successive clutches of fertilized eggs. Estimates of maximal rates of clutch production based on this measure were more than three times higher than those based on the duration of embryonic development. Since unfertilized oocytes disintegrate upon extrusion, a considerable amount of reproductive material may be wasted regularly. A turnover rate of 5.6% body weight (dry) day-1 was calculated for isolated females at 18° C. A model used to estimate the frequency of mating interactions indicated that the probability of oocyte extrusion in lakes may be high and the impact on nutrient pools could be substantial. Up to 0.12 μg phosphorus mg-1 h-1 may be released in the form of unfertilized oocytes.

Vacuum behavior in quantum chromodynamics. II

Abstract: Vacuum polarization contributions due to fermions or scalars produced by gluon background-field fluctuations indicate vacuum instability in quantum chromodynamics; the instability is quantitatively related to pair-creation processes. The results extend previous work on gluonic contributions, and generalize the similar quantum-electrodynamic results of Euler and Heisenberg and Schwinger.

Space partitioning and interactions in an intertidal sand-burrowing amphipod guild

Abstract: A nine-year study at a moderately exposed, fine sand intertidal beach at Long Sands, Maine, USA identified marked seasonal changes in the foci of sand-burrowing amphipod activities. These included seasonal population movements, degree of interspecific horizontal overlap, life stage segregation within and between species, and sand depth stratification. Behavioral interactions related to competition for available space are considered important in affecting the distribution and abundance of amphipod species, and community structure. Significant negative correlations were shown between the abundance and upper distributional limits of the smaller, lower shore Acanthohaustorius millsi and the abundance of the larger, higher shore species Haustorius canadensis. Tolerance limits to a variety of prevailing physical factors alone, were not considered a serious obstacle to occupation of higher intertidal level sands by A. millsi. Summer brooding females of both species occupied similar 5 to 10 cm sand depths, but were strongly segregated horizontally. Laboratory coexistence experiments during the reproductive period showed increased mortality of adults and negligible reproductive output of A. millsi when in combination with H. canadensis compared to controls where the former species was alone. A third species, Amphiporeia virginiana, occupied primarily very shallow sand (0 to 2.5 cm), and performed seasonal movements opposite in direction to A. millsi and H. canadensis. The presence, amount, and refinement of biological interactions across the wave exposure gradient requires further study. Until then, we consider as inappropriate the blanket designation of all types of intertidal sand communities as “physically controlled”.

A Hierarchy of Attitudes Toward Exceptionality

Abstract: The responses of 122 university students to 24 statements expressing attitudes toward the school integration and community integration of 11 groups of exceptionality and the normal were submitted to an ordering-theoretic data-analysis procedure. The nonlinear hierarchy of contingent relationships among the exceptionalities in each attitude domain were interpreted with reference to previous research and contemporary special education theory and practice. The results illustrate the usefulness of ordering theory, a new measurement model, for building a theory concerning the interrelated network of attitudes toward exceptionalities.

NCTR Plus Sensor Fusion Equals IFFN or can Two Plus Two Equal Five

Abstract: Fowler's Seventh Law for military systems [1] states: "Be wary of proposals for synergistic systems. Most of the time when you try to make 2 + 2 = 5, you end up with 3-and sometimes 1.9." We attempt to approach the broad issues of IFFN (identification, friend, foe, neutral) of military targets via the techniques of NCTR (noncooperative target recognition), coupled with the systems approach called "sensor fusion." Although the overall style of the paper is that of a tutorial, many of the results presented are original. In all cases where we make political obsrvations, they represent our personal opinions.

GABA and taurine derivatives on the adhesive spiral of the orb web of Argiope spiders, and their possible behavioural significance

Abstract: . Two strongly acidic, ninhydrin-negative compounds were found in the water soluble fraction of the orb webs of Argiope trifasciata (Lucas) and Argiope aurantia (Forskal). One of these is a derivative of taurine. Aninhydrin-positive GABA derivative, gabamide, also exists in the water-soluble fraction of the web.