Showing papers by "University of Liverpool published in 1997"
TL;DR: The emerging discipline of restoration ecology as mentioned in this paper provides a powerful suite of tools for speeding the recovery of degraded lands, and provides a crucial complement to the establishment of nature reserves as a way of increasing land for the preservation of biodiversity.
Abstract: Conversion of natural habitats into agricultural and industrial landscapes, and ultimately into degraded land, is the major impact of humans on the natural environment, posing a great threat to biodiversity. The emerging discipline of restoration ecology provides a powerful suite of tools for speeding the recovery of degraded lands. In doing so, restoration ecology provides a crucial complement to the establishment of nature reserves as a way of increasing land for the preservation of biodiversity. An integrated understanding of how human population growth and changes in agricultural practice interact with natural recovery processes and restoration ecology provides some hope for the future of the environment.
860 citations
TL;DR: The resolution of this apparent paradox may be that the response of adult size to temperature is adaptive, but is constrained by a trade-off that can be understood in terms of von Bertalanffy's classic theory of growth.
Abstract: Environmental effects on body size are of widespread ecological and economic importance but our understanding of these effects has been obscured by an apparent paradox. Life history analysis suggests that it is adaptive for adults to emerge smaller if reared in conditions that slow down juvenile growth. However, whereas smaller adults emerge if growth is limited by food availability, the reverse is usually observed if growth is limited by temperature. The resolution of this apparent paradox may be that the response of adult size to temperature is adaptive, but is constrained by a trade-off that can be understood in terms of von Bertalanffy's classic theory of growth. Alternatively, the response may be the unavoidable consequence of a fundamental relationship between cell size and temperature.
745 citations
702 citations
TL;DR: In the process of removing the desired mineral material, original soils become lost, or buried by wastes as discussed by the authors, and a vast heritage of degraded land left by past mining that requires restoration.
632 citations
Journal Article•
TL;DR: It is found that human MAdCAM-1, as in the mouse, is expressed in a tissue-selective manner and may be a relevant tissue-specific therapeutic target for the modulation of inflammatory bowel disease activity.
Abstract: Lymphocyte homing to normal tissues and recruitment to inflammatory tissue sites are controlled, in part, by the selective expression of chemokines, pro-inflammatory cytokines and mediators, and various adhesion proteins and molecules. In the mouse, mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is selectively expressed on endothelium of high endothelial venules in gut and gut-associated lymphoid tissue. By interaction with its integrin ligand, alpha 4 beta 7, lymphocytes presumed to be involved in mucosal immunity are selectively recruited to these intestinal sites. After generating monoclonal antibodies against a murine cell line expressing recombinant human MAdCAM-1, we qualitatively and semiquantitatively assessed MAdCAM-1 expression in human tissue sections from various normal and inflammatory disorders. We found that human MAdCAM-1, as in the mouse, is expressed in a tissue-selective manner. In normal tissues, MAdCAM-1 is constitutively expressed to endothelium of venules of intestinal lamina propria. Interestingly, using computer-assisted morphometric analysis, the proportion of venular endothelium within lamina propria that expresses MAdCAM-1 is increased, compared with normal tissues, at inflammatory foci associated with ulcerative colitis and Crohn's disease. Moreover, for the most part, MAdCAM-1 is not detected in the majority of normal or inflamed extra-intestinal tissues, including those with mucosal surfaces. These results are consistent with a role, as originally defined in the mouse, for human MAdCAM-1 in the localization of alpha 4 beta 7+ lymphocytes in the gastrointestinal tract and associated lymphoid tissue. As such, the pathway defined by MAdCAM-1/alpha 4 beta 7 may be a relevant tissue-specific therapeutic target for the modulation of inflammatory bowel disease activity.
608 citations
TL;DR: The authors describe social cognition and differentiate it from nonsocial cognition and describe the potential implications of a social-cognitive model of schizophrenia for the etiology and development of the disorder.
Abstract: The study of social cognition in schizophrenia may augment the understanding of clinical and behavioral manifestations of the disorder. In this article, the authors describe social cognition and differentiate it from nonsocial cognition. They garner evidence to support the role of social cognition in schizophrenia: Nonsocial information-processing models are limited to explain social dysfunction in schizophrenia, measures of social cognition may contribute greater variance to social functioning than measures of nonsocial cognition, task performance on nonsocial-cognitive measures may not parallel performance on social-cognitive tasks, and symptomatology may be best understood within a social-cognitive framework. They describe the potential implications of a social-cognitive model of schizophrenia for the etiology and development of the disorder.
607 citations
TL;DR: In this paper, a set of many-body interatomic potentials has been developed for the Fe-Cu system, including modifications to ensure suitability for simulating atomic collisions at high energy.
Abstract: The behaviour of copper atoms in dilute solution in α-iron is important for the microstructural changes that occur in ferritic pressure vessel steels under fastneutron irradiation. To investigate the properties of atomic defects that control this behaviour, a set of many-body interatomic potentials has been developed for the Fe—Cu system. The procedures employed, including modifications to ensure suitability for simulating atomic collisions at high energy, are described. The effect of copper on the lattice parameter of iron in the new model is in good agreement with experiment. The phonon properties of the pure crystals and, in particular, the influence of the instability of the metastable, bcc phase of copper that precipitates during irradiation are discussed. The properties of point defects have been investigated. It is found that the vacancy has lower formation and migration energy in bcc copper than in α-iron, and the self-interstitial atom has very low formation energy in this phase of coppe...
603 citations
TL;DR: It is found that both the gonadosomatic index and sperm numbers increase with intensity of sperm competition across species but that sperm length decreases, which does not fit predictions of current sperm competition theory.
Abstract: Fishes show one of the widest ranges of sperm competition intensity of any animal group. Here we present a comparative study whose aim is to investigate the effect of relative intensity of sperm competition on investment in spermatogenesis and the number and size of sperm produced. We find that both the gonadosomatic index (GSI5 (gonad weight/body weight) 3 100) and sperm numbers increase with intensity of sperm competition across species but that sperm length decreases. These new findings are consistent with a raffle-based mode of sperm competition in fishes. Most of these results (positive correlation of the GSI and sperm number with sperm competition intensity) concur with the predictions of current sperm competition the- ory. However, we also find that sperm longevity decreases with sperm length across species. Cur- rent models for continuous fertilization suggest that if length increases a sperm's speed but de- creases its longevity, sperm length should increase with sperm competition intensity, whereas models for instant fertilization suggest that sperm length should remain constant. The negative relationship found between sperm competition and sperm length therefore does not fit predictions of either model.
576 citations
TL;DR: In critically ill ICU patients unable to receive enteral nutrition, a Gln-containing parenteral nutrition solution improves survival at 6 mo and reduces the hospital costs per survivor.
546 citations
TL;DR: VLBW children are at increased risk of psychiatric symptoms especially ADHD, and the main psychiatric risk was Attention Deficit Hyperactivity (ADH) disorders.
Abstract: One hundred and thirty-seven very low birthweight (VLBW) children were compared at 12 years with a sample of matched peers on a number of psychiatric symptoms including Attention Deficit/Hyperactivity Disorder, depression, anxiety, and antisocial behaviour using the Child and Adolescent Psychiatric Assessment parent interview and various parent and child questionnaires. The main psychiatric risk was Attention Deficit Hyperactivity (ADH) disorders, with 31/136 (23%) VLBW children meeting clinical criteria, compared to 9/148 (6%) of peers. VLBW children were also more likely to have generalised anxiety and more symptoms of depression. More than one quarter of VLBW children (38/136; 28%) showed a psychiatric disorder of some type compared to 9% (14/148) of peers. VLBW children are at increased risk of psychiatric symptoms especially ADHD. This outcome is discussed in relation to neurological, demographic, and cumulative impairment factors.
472 citations
TL;DR: It is demonstrated that orf73 encodes the 222- to 234-kDa LNA, is a component of LANA, and is expressed in KS tumor cells, as well as the characteristic speckled nuclear immunofluorescence pattern ofLANA on Western blots.
Abstract: Kaposi's sarcoma (KS)-associated herpesvirus or human herpesvirus 8 (KSHV/HHV8) is the likely cause of KS and primary effusion lymphomas or body cavity-based lymphomas (BCBLs). A latency-associated nuclear immunofluorescence antigen (LANA) (D. H. Kedes, E. Operskalski, M. Busch, R. Kohn, J. Flood, and D. Ganem, Nat. Med. 2:918-924, 1996; S. J. Gao, L. Kingsley, M. Li, W. Zheng, C. Parravicini, J. Ziegler, R. Newton, C. R. Rinaldo, A. Saah, J. Phair, R. Detels, Y. Chang, and P. S. Moore, Nat. Med. 2:925-928, 1996) and a 222- to 234-kDa nuclear protein (LNA) (S. J. Gao, L. Kingsley, D. R. Hoover, T. J. Spira, C. R. Rinaldo, A. Saah, J. Phair, R. Detels, P. Parry, Y. Chang, and P. S. Moore, N. Engl. J. Med. 335:233-241, 1996) have previously been described in BCBL cell lines by immunofluorescence and Western blotting techniques, respectively. To identify the viral gene(s) encoding this antigen(s) we screened a cDNA library from HBL-6 cells, a B-cell lymphoma cell line persistently infected with KSHV/HHV8, with KS patient sera. One set of positive clones contained the 3' end of orf73, as well as the complete orf72 and orfK13, and another set contained the 5' end of orf73. Comparison of cDNA sequences with the KSHV/HHV8 genomic sequence revealed a splice event, occurring upstream of orf73. Immunoaffinity purified antibodies to a recombinant carboxy-terminal fragment of the orf73-encoded protein showed the characteristic speckled nuclear immunofluorescence pattern of LANA and reacted with the 222- to 234-kDa LNA on Western blots. Expression of full-length orf73 in bacteria and COS7 cells reproduced the LNA banding pattern. Immunohistochemistry on cases of nodular KS revealed that orf73/LNA is expressed in the nucleus of KS spindle cells. These findings demonstrate that orf73 encodes the 222- to 234-kDa LNA, is a component of LANA, and is expressed in KS tumor cells.
TL;DR: Fear of recurrence is recognised in the literature, but few researchers have focused on this aspect as a precursor to psychological distress.
Abstract: Modern treatments for cancer are resulting in cancer patients living longer with the risk of the disease returning at a later stage. Many patients who experience a recurrence blame themselves (Mahon et al., 1990), while those in remission live with the constant fear that the cancer may return. Although fear of recurrence is recognised in the literature, few researchers have focused on this aspect as a precursor to psychological distress. This paper reviews the literature about fear of recurrence and its measurement. Leventhal's Self Regulation Model of Illness is presented to help understand patients' reactions to cancer and fears for the future. The authors propose a formulation for fear of recurrence and examples of interventions that are indicated.
TL;DR: Electron density calculations suggest that the different reactivities cannot be attributed solely to differences in electron distribution along the polyene chain of the different chromophores, which would alter the susceptibility to free-radical addition to the conjugated double-bond system.
Book•
12 Jun 1997TL;DR: This third edition of this comprehensive textbook provides key information on how animals grow and change in shape and composition, and the factors that affect these processes.
Abstract: An understanding of the processes that change the shape and composition of farm animals is fundamental to all aspects of production. Updated to include new chapters on avian growth and global warming, and citing new research throughout, this comprehensive textbook provides key information on how animals grow and change in shape and composition, and the factors that affect these processes. Presented in a larger format with new photographs and focus boxes, this third edition continues to fill the important role of helping to understand how the basics of growth must be thoroughly understood if farm animals are to be used efficiently and humanely in producing food for mankind.
TL;DR: The logic of assessment of sperm Competition risk by individual males where the mechanism of sperm competition follows a ‘loaded raffle’ is developed and biological evidence for the predictions is summarized and discussed.
Abstract: We develop the logic of assessment of sperm competition risk by individual males where the mechanism of sperm competition follows a 'loaded raffle' (first and second inseminates of a female have unequal prospects). Male roles (first or second to mate) are determined randomly. In model 1, males have no information about the risk associated with individual females and ejaculation strategy depends only on the probability, q, that females mate twice. Evolutionarily stable strategy (ESS) ejaculate expenditure increases linearly from zero with q, and reduces with increasing inequality between ejaculates, though the direction of the loading (which role is favoured) is unimportant. In model 2, males have perfect information and can identify each of three risk states: females that will (1) mate just once ('no risk'), (2) mate twice but have not yet mated ('future risk'), and (3) mate twice and have already mated ('past risk'). The ESS is to ejaculate minimally with 'no risk' females, and to expand equally with 'past' and 'future' risk females; the direction of the competitive loading is again unimportant. Expenditure again increases with risk, but is now non-zero at extremely low risk. Model 3 examines three cases of partial information where males can identify only one of the three risk states and cannot distinguish between the other two: they therefore have just two information sets or 'contexts'. Expenditure in both contexts typically rises non-linearly from zero with q, but (whatever the loading direction) expenditure is higher in the context with higher risk (e.g. if contexts are 'mated' and 'virgin', males spend more with mated females). However, in highly loaded raffles, sperm expenditure can decrease over part of the range of risk. Also, the direction of the loading now affects expenditure. Biological evidence for the predictions of the models is summarized and discussed.
TL;DR: A series of meta‐analyses of randomized placebo‐controlled add‐on trials in which these drugs have been tested in patients with partial epilepsy are reported, providing an estimate of each drug's efficacy and tolerability compared with placebo.
Abstract: Summary
: Purpose: Gabapentin (GBP), lamotrigine (LTG), tiagabine (TGB), topiramate (TPM), vigabatrin (VGB), and zonisamide (ZNS) are all in use as “add-on” treatment for patients with refractory epilepsy. There have been no comparative randomized controlled trials allowing an evidence-based choice between these drugs. We report a series of meta-analyses of randomized placebo-controlled add-on trials in which these drugs have been tested in patients with partial epilepsy. This work provides an estimate of each drug's efficacy and tolerability compared with placebo. These estimates are compared across drugs to give broad estimates of comparative efficacy and tolerability.
Methods: Trial reports were found by searching Medline, by searching through journals by hand, and by contacting the pharmaceutical industry. The outcomes chosen were the proportion of patients who (a) have a 350% reduction in seizure frequency (50% responders); (b) withdrew from the study (any reason); or (c) reported the following side effects: ataxia, dizziness, fatigue, nausea, or somnolence. Overall odds ratio (OR) with 95% confidence intervals (CIS; 50% responders) or 99% CIS; side effects) were calculated.
Results: Twenty-nine trials were included, representing 4,091 randomized patients. The ORs for 50% response (95% CI) were GBP, 2.29 (1.53–3.43); LTG, 2.32 (1.47–3.68); TGB, 3.03 (2.01–4.58); TPM, 4.07 (2.87–5.78); VGB, 3.67 (2.44–5.51); and ZNS, 2.7 (1.36–4.47). ORs for discontinuation were GBP, 1.36 (0.75–2.49); LTG, 1.19 (0.79–1.79); TGB, 1.81 (1.21–2.70); TPM, 2.56 (1.64–4.00); VGB, 2.58 (126–5.27); and ZNS, 4.23 (1.71–10.49).
Conclusions: We have clear evidence that each of these drugs is better than placebo at preventing seizures. When results are compared across drugs, the confidence intervals overlap, and we have no conclusive evidence of differences in efficacy or tolerability. Despite this, the agent that appears most effective may be twice as effective as the agent that appears least effective, and the agent that appears most likely to cause discontinuation may be 4 times more likely to do so than the treatment that appears least likely to do so. Comparative randomized studies are needed further to evaluate these drugs.
TL;DR: The properties of amorphous carbon (a-C) deposited using a filtered cathodic vacuum arc as a function of the ion energy and substrate temperature are reported in this paper.
Abstract: The properties of amorphous carbon (a-C) deposited using a filtered cathodic vacuum arc as a function of the ion energy and substrate temperature are reported. The sp3 fraction was found to strongly depend on the ion energy, giving a highly sp3 bonded a-C denoted as tetrahedral amorphous carbon (ta-C) at ion energies around 100 eV. The optical band gap was found to follow similar trends to other diamondlike carbon films, varying almost linearly with sp2 fraction. The dependence of the electronic properties are discussed in terms of models of the electronic structure of a-C. The structure of ta-C was also strongly dependent on the deposition temperature, changing sharply to sp2 above a transition temperature, T1, of ≈200 °C. Furthermore, T1 was found to decrease with increasing ion energy. Most film properties, such as compressive stress and plasmon energy, were correlated to the sp3 fraction. However, the optical and electrical properties were found to undergo a more gradual transition with the deposition temperature which we attribute to the medium range order of sp2 sites. We attribute the variation in film properties with the deposition temperature to diffusion of interstitials to the surface above T1 due to thermal activation, leading to the relaxation of density in context of a growth model.
TL;DR: Weak isosinglet neutral heavy leptons (m) have been searched for using data collected by the DELPHI detector corresponding to 3:3 106 hadronic Z0 decays at LEP1.
Abstract: Weak isosinglet Neutral Heavy Leptons (m) have been searched for using data collected by the DELPHI detector corresponding to 3:3 106 hadronic Z0 decays at LEP1. Four separate searches have been performed, for short-lived m production giving monojet or acollinear jet topologies, and for long-lived m giving detectable secondary vertices or calorimeter clusters. No indication of the existence of these particles has been found, leading to an upper limit for the branching ratio BR(Z0 ! m) of about 1:310−6 at 95% confidence level for m masses between 3.5 and 50 GeV/c2. Outside this range the limit weakens rapidly with the m mass. The results are also interpreted in terms of limits for the single production of excited neutrinos.
TL;DR: A key key word is shown to have associates: words that are key in the same texts as a given key key words, which themselves are revealing about text schemata and stereotype.
TL;DR: The mer operon provides a model system in the study of environmental microbiology which is useful both as an example of a genotype which is responsive to environmental pressures and as a generic tool for the development of new methodology for the analysis of bacterial communities in natural environments.
Abstract: Mercury and its compounds are distributed widely across the earth. Many of the chemical forms of mercury are toxic to all living organisms. However, bacteria have evolved mechanisms of resistance to several of these different chemical forms, and play a major role in the global cycling of mercury in the natural environment. Five mechanisms of resistance to mercury compounds have been identified, of which resistance to inorganic mercury (HgR) is the best understood, both in terms of the mechanisms of resistance to mercury and of resistance to heavy metals in general. Resistance to inorganic mercury is encoded by the genes of the mer operon, and can be located on transposons, plasmids and the bacterial chromosome. Such systems have a worldwide geographical distribution, and furthermore, are found across a wide range of both Gram-negative and Gram-positive bacteria from both natural and clinical environments. The presence of mer genes in bacteria from sediment cores suggest that mer is an ancient system. Analysis of DNA sequences from mer operons and genes has revealed genetic variation both in operon structure and between individual genes from different mer operons, whilst analysis of bacteria which are sensitive to inorganic mercury has identified a number of vestigial non-functional operons. It is hypothesised that mer, due to its ubiquity with respect to geographical location, environment and species range, is an ancient system, and that ancient bacteria carried genes conferring resistance to mercury in response to increased levels of mercury in natural environments, perhaps resulting from volcanic activity. Models for the evolution of both a basic mer operon and for the Tn21-related family of mer operons and transposons are suggested. The study of evolution in bacteria has recently become dominated by the generation of phylogenies based on 16S rRNA genes. However, it is important not to underestimate the roles of horizontal gene transfer and recombinational events in evolution. In this respect mer is a suitable system for evaluating phylogenetic methods which incorporate the effects of horizontal gene transfer. In addition, the mer operon provides a model system in the study of environmental microbiology which is useful both as an example of a genotype which is responsive to environmental pressures and as a generic tool for the development of new methodology for the analysis of bacterial communities in natural environments.
TL;DR: The ability of carotenoids to protect egg-yolk phosphatidylcholine lipids against oxidation by peroxyl radicals generated from azo-initiators was studied and Lycopene was destroyed most rapidly but was least effective as an antioxidant.
TL;DR: In this article, the authors investigated three regions of the Western Chinese Loess Plateau in order to recover records of monsoon climate variations and found that numerous rapid changes in climate occurred in China during the last glacial cycle, but that the range of climate variations was smaller than recorded in Greenland.
TL;DR: Findings support R. Kaney's (1994) defensive attributional model of persecutory delusions, suggest some modifications to that model, and have implications for the understanding of the relationship between causal attributions and social and self-perception.
Abstract: Causal attributions for positive and negative hypothetical social events made by paranoid patients, depressed patients, and nonpatient participants were examined via a novel measure of causal locus, the Internal, Personal and Situational Attributions Questionnaire. Depressed patients tended to attribute negative social events to internal (self-blaming) causes. Nonpatient participants and patients with delusions of persecution tended to avoid such self-blame. However, whereas nonpatient participants tended to choose situational or circumstantial external attributions, paranoid patients tended to choose external attributions that located blame in other individuals. These findings support R. P. Bentall, P. Kinderman, and S. Kaney's (1994) defensive attributional model of persecutory delusions, suggest some modifications to that model, and have implications for the understanding of the relationship between causal attributions and social and self-perception.
TL;DR: The spin-coupled (SC) theory of molecular electronic structure is introduced as the modern development of classical valence bond (VB) theory as mentioned in this paper, and applications of the SC description to a range of different kinds of chemical problems are presented, beginning with simple examples: the H2 and CH4 molecules.
Abstract: The spin-coupled (SC) theory of molecular electronic structure is introduced as the modern development of classical valence bond (VB) theory. Various important aspects of the SC wave function are described. Attention is particularly focused on the construction and properties of different sets of N-electron spin function in different spin bases, such as the Kotani, Rumer and Serber. Applications of the SC description to a range of different kinds of chemical problems are presented, beginning with simple examples: the H2 and CH4 molecules. This is followed by the description offered by the SC wave function of more complex situations such as the insertion reaction of H2 into CH2(1A1), the phenomenon of hypervalence as displayed by molecules such as diazomethane, CH2N2, SF6 and XeF2. The SC description of the ground and excited states of benzene is briefly surveyed. This is followed by the SC description of antiaromatic systems such as C4H4 and related molecules.
21 Feb 1997-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: The H1 detector at the electron-proton storage ring HERA as mentioned in this paper was used from 1992 to the end of 1994, and a major upgrade of some components was undertaken.
Abstract: General aspects of the H1 detector at the electron-proton storage ring HERA as well as technical descriptions of the magnet, luminosity system, trigger, slow-control, data acquisition and off-line data handling are given. The three major components of the detector, the tracking, calorimeter and muon detectors, will be described in a forthcoming article. The present paper describes the detector that was used from 1992 to the end of 1994. After this a major upgrade of some components was undertaken. Some performance figures from luminosity runs at HERA during 1993 and 1994 are given.
TL;DR: Observational studies of human conversations in relaxed social settings suggest that these consist predominantly of exchanges of social information (mostly concerning personal relationships and experiences), and most of these exchanges involve information about the speaker or third parties, and very few involve critical comments or the soliciting or giving of advice.
Abstract: Observational studies of human conversations in relaxed social settings suggest that these consist predominantly of exchanges of social information (mostly concerning personal relationships and experiences). Most of these exchanges involve information about the speaker or third parties, and very few involve critical comments or the soliciting or giving of advice. Although a policing function may still be important (e.g., for controlling social cheats), it seems that this does not often involve overt criticism of other individuals’ behavior. The few significant differences between the sexes in the proportion of conversation time devoted to particular topics are interpreted as reflecting females’ concerns with networking and males’ concerns with self-display in what amount to a conventional mating lek.
TL;DR: Leptin acts centrally to decrease NPY synthesis and NPY levels in the ARC-PVN projection; reduced NPY release in the PVN may mediate leptin's hypophagic and thermogenic actions; Conversely, NPY-induced obesity results in raised circulating leptin concentrations.
Abstract: Leptin acts on the brain to inhibit feeding, increase thermogenesis, and decrease body weight. Neuropeptide Y (NPY)-ergic neurons of the hypothalamic arcuate nucleus (ARC) that project to the paraventricular nuclei (PVN) and dorsomedial nuclei (DMH) are postulated to control energy balance by stimulating feeding and inhibiting thermogenesis, especially under conditions of energy deficit. We investigated whether leptin's short-term effects on energy balance are mediated by inhibition of the NPY neurons. Recombinant murine leptin (11 microg) injected into the lateral ventricle of fasted adult Wistar rats inhibited food intake by 20-25% between 2 and 6 h after administration, compared with saline-treated controls (P 0.1), but plasma leptin levels were significantly higher (4.88 +/- 0.66 vs. 2.85 +/- 0.20 ng/ml; P < 0.01). Leptin therefore acts centrally to decrease NPY synthesis and NPY levels in the ARC-PVN projection; reduced NPY release in the PVN may mediate leptin's hypophagic and thermogenic actions. Conversely, NPY-induced obesity results in raised circulating leptin concentrations. Leptin and the NPY-ergic ARC-PVN neurons may interact in a homeostatic loop to regulate body fat mass and energy balance.
01 Mar 1997
TL;DR: ASSYST offers a graphical interface that can be used to direct all aspects of the grading process, and it considers a wide range of criteria in its automatic assessment.
Abstract: The task of grading solutions to student programming exercises is laborious and error-prone. We have developed a software tool called ASSYST that is designed to relieve a tutor of much of the burden of assessing such programs. ASSYST offers a graphical interface that can be used to direct all aspects of the grading process, and it considers a wide range of criteria in its automatic assessment. Experience with the system has been encouraging.
TL;DR: In this article, surface x-ray diffraction has been used to determine the structural relaxations of the titanium planes, and the results of three independent calculations of the energy minimization structure were compared with the positions of the predicted positions of titanium atoms predicted by Ramamoorthy et al.
Abstract: Surface x-ray diffraction has been used to determine the structural relaxations of ${\mathrm{TiO}}_{2}(110)\ensuremath{-}(1\ifmmode\times\else\texttimes\fi{}1)$. The magnitudes range from 0 to 0.27 \AA{}, leading to rumpling of the titanium planes. The data are compared to the results of three independent calculations of the energy minimized structure. Excellent agreement is achieved with the positions of titanium atoms predicted by Ramamoorthy et al. [Phys. Rev. B 49, 16 721 (1994)].
TL;DR: Recent work demonstrates an even greater antiviral effect from triple therapy with 2 nucleosides, zidovudine plus zalcitabine with the addition of saquinavir, a new protease inhibitor drug.
Abstract: Since its introduction in 1987, zidovudine monotherapy has been the treatment of choice for patients with HIV infection. Unfortunately it has been established that the beneficial effects of zidovudine are not sustained due to the development of resistant viral strains. This has led to the strategy of combination therapy, and in 1995 treatment with zidovudine plus didanosine, or zidovudine plus zalcitabine, was demonstrated to be more effective than zidovudine monotherapy in preventing disease progression and reducing mortality in patients with HIV disease.