The human genome project: a reply to Rosenberg

In this paper we discuss the scientific value of the human genome project. To what extent is the data obtained by sequencing the entire human genome useful in the gene dicovery process? Responding to Alex Rosenberg' skepticism about the value of such data, we maintain that brute sequence data is much more useful than he suggests.     

Paleopathology of Toyotamaphimeia machikanensis (Diapsida,Crocodylia) from the Middle Pleistocene of Central Japan

The type specimen of Toyotamaphimeia machikanensis (Diapsida, Crocodylia) from the Osaka Group (Plio-Pleistocene) of Osaka Prefecture, Central Japan, shows multiple abnormalities. The anterior third of the mandible was amputated and shows signs of healing. The right tibia and fibula were fractured, and each of them was later fused in dislocated position with callus formation. Additionally, there are two puncture marks on a dermal scute. Based on the morphologies of these pathologies, the fauna of the community in which this animal lived, and the behavior of extant crocodilians, it is suggested that this individual survived its injuries sustained during multiple intraspecific fights for territoriality or mating.     

An alien approach to invasive species: objectivity and society in invasion biology

Several authors have recently argued that invasion biologists should adopt a more objective and dispassionate stance towards invasive species. Brown and Sax (Austral Ecol 29:530–536, 2004; Austral Ecol 30:481–483, 2005) assert that invasion biologists risk their objectivity, “commit the naturalist fallacy” or “embark on a slippery slope” with engaged concern about invasive species. Elsewhere, Colautti and MacIsaac (Divers Distrib 10:135–141, 2004) propose a neutral language for invasion biology, one that insulates scientific from popular discussion about invasive species. While there is certainly hyperbole about the effects of some invasive species, the type of objectivity promoted in these papers may often be inappropriate for invasion biology. It implies a policy of non-action that is inconsistent with the conservation values of many invasion biologists. To engage these values, invasion biologists can adopt deliberative methods for environmental problem-solving that involve stakeholders in their research design and which still promote high standards of scientific rigor.     

Fitness in animals correlates with proximity to discontinuities in body mass distributions

Discontinuous structure in landscapes may cause discontinuous, aggregated species body-mass patterns, reflecting the scales of structure available to animal communities within a landscape. Empirical analyses have shown that the location of species within body mass aggregations, which reflect this scale-specific organization, is non-random with regard to several ecological phenomena, including species extinctions. The propensity of declining species to have body masses proximate to discontinuities suggests that transition zones between scaling regimes ultimately decreases the ecological fitness for some species. We test this proposition using vulnerable and unthreatened fish species in Mediterranean streams with differing levels of human impact. We show that the proximity to discontinuities in body mass aggregations (“distance-to-edge”) of more vs. less fit individuals within vulnerable and unthreatened populations differs. Specifically, regression analysis between the scaled mass index, a proxy of animal fitness, and distance-to-edge reveals negative and positive relationships for vulnerable and unthreatened species, respectively. That is, fitness is higher close to discontinuities in vulnerable populations and toward the center of body mass aggregation groups in unthreatened populations. Our results demonstrate the suitability of the discontinuity framework for scrutinizing non-random patterns of environmental impact in populations. Further exploration of the usefulness of this method across other ecosystems and organism groups is warranted.     

The conservation and tourism development of World Natural Heritage sites: The current situation and future prospects of research

The conservation and tourism development of World Heritage (WH) sites has always been a key and urgent scientific issue to be solved urgently by academia and industry all over the world. An increasing number of researchers and practitioners are paying attention to this issue. However, there is a lack of a comprehensive literature review on this topic. To fill this gap, this study conducts a systematic literature review (SLR) based on 179 related studies retrieved from the Web of Science (WoS) and Google Scholar (GS) databases. Focusing on the research question of the conservation and tourism development of World Natural Heritage (WNH) sites, we built an SLR framework to implement the review process. First, quantitative research was conducted to analyse the annual numbers, content and continents of the published literature. Second, we classified and summarized the main progress and achievements from theoretical research, technical methods, model construction, monitoring and evaluating, and application demonstration. Finally, in view of the current research situation of the conservation and tourism development of WNH sites, we proposed eight key scientific issues to be solved and several directions for future research.     

Evaluation of the fluorescein diacetate (FDA) vital dye viability test with hamster and bovine embryos

A study was undertaken to determine: (1) the potential toxicity of a fluorogenic vital dye, fluorescein diacetate (FDA), on hamster and bovine pre-implantation embryos; and (2) whether a correlation exists between the fluorescence of an embryo and its ability to continue development.For the toxicity trial, hamster eight-cell embryos were randomly assigned to one of three groups (control, FDA+UV light or UV light only), and early bovine blastocysts to either a control or FDA+UV light group. Embryos were cultured for 24 h and scored for development to the blastocyst stage. Embryos of both species developed equally well in vitro regardless of whether or not they had been exposed to FDA and UV light. Treated and untreated control embryos from both species were transferred to synchronized recipients. Similar numbers of pregnancies resulted after transfer of treated and untreated embryos from both species.In the second experiment, the proportions of fluorescing embryos were compared using two groups of hamster eight-cell embryos: (1) freshly collected embryos; and (2) cultured embryos that failed to develop. Significantly more of the fresh eight-cell embryos fluoresced than did the cultured, undeveloped embryos. No false negative results were obtained (embryos that developed but failed to fluoresce). However, approximately half of the non-developing, cultured embryos showed varying degrees of fluorescence (false positive). Embryos showing “false positive” fluorescence may be viable, but incapable of further development due to deficiencies of the culture medium.The procedures used in the FDA viability assay were not detrimental to development of late cleavage stage mammalian embryos and thus seem suitable for rapid screening of manipulated embryos for potential damage. However, further work is needed to establish the significance of the false positive results encountered in this study.     

Purification and characterization of osmoregulatory betaine aldehyde dehydrogenase of Escherichiacoli

The osmoregulatory NAD-dependent betaine aldehyde dehydrogenase (betaine aldehyde: NAD oxidoreductase, EC 1.2.1.8), of Escherichia coli, was purified to apparent homogeneity from an over-producing strain carrying the structural gene for the enzyme (betB) on the plasmid vector pBR322. Purification was achieved by ammonium sulfate fractionation of disrupted cells, followed by affinity chromatography on 5′-AMP Sepharose, gel-filtration and ion-exchange chromatography. The amino acid composition was determined. The dehydrogenase was found to be a tetramer with identical 55 kDa subunits. Both NAD and NADP could be used as cofactor for the dehydrogenase, but NAD was preferred. The dehydrogenase was highly specific for betaine aldehyde. None of the analogs tested functioned as a substrate, but several inhibited the enzyme competitively. The enzyme was not activated by salts at concentrations encountered during osmotic upshock, but it was salt tolerant, retaining 50% of maximal activity at 1.2 M K⁺. It is inferred that salt tolerance is an essential property for an enzyme participating in the cellular synthesis of an osmoprotectant.     

Immune unresponsiveness of spleen cells from lipopolysaccharide-sensitized mice to particulate thymus-dependent antigens. II. Evidence for an abortive cooperation between T lymphocytes and antigen-presenting cells

LPS-induced immune unresponsiveness has been shown to be related to an impaired production of differentiation signal factor(s). The mechanism underlying this phenomenon was analyzed. The in vitro anti-SRBC response of spleen cells from normal mice was not suppressed by addition of LPS-treated spleen cells, ruling out a possible implication of active suppressor cells. Immune responsiveness concomitant with TRF production was restored in LPS-sensitized cells upon addition of 2-ME. The role of adherent and nonadherent cells was also investigated; both cell populations from LPS-treated mice were able to collaborate with their normal counterparts showing that the defective TRF production results from synergistic effects of LPS-induced alterations concerning both adherent and T-cell populations.