Plant‐frugivore interactions in an intact tropical forest in north‐east Thailand

Fleshy‐fruited plants in tropical forests largely rely on vertebrate frugivores to disperse their seeds. Although this plant–animal interaction is typically considered a diffuse mutualism, it is fundamental as it provides the template on which tropical forest communities are structured. We applied a mutualistic network approach to investigate the relationship between small‐fruited fleshy plant species and the fruit‐eating bird community in an intact evergreen forest in northeast Thailand. A minimum of 53 bird species consumed fruits of 136 plant species. Plant‐avian frugivore networks were highly asymmetrical, with observed networks filling 30% of all potential links. Whereas some of the missing links in the present study might be due to undersampling, forbidden links can be attributed to size constraints, accessibility and phenological uncoupling, and although the majority of missing links were unknown (58.2%), many were probably due to a given bird species being either rare or only a very occasional fruit eater. The most common frugivores were bulbuls, barbets and fairy‐bluebirds, which were responsible for the majority of fruit removal from small fleshy fruited species in our system. Migratory birds seemed to be a minor component of the plant‐frugivore networks, accounting for only 3% of feeding visits to fruiting trees; they filled 2% of the overall potential networks. The majority of interactions were generalized unspecific; however, Saurauia roxburghii Wall. appeared to be dependent on flowerpeckers for dispersal, while Thick‐billed Pigeons were only seen to eat figs.     

Regional Sediment Deficits in the Dutch Lowlands: Implications for Long-Term Land-Use Options (8 pp)

Background, Aim and Scope   Coastal and river plains are the surfaces of depositional systems, to which sediment input is a parameter of key-importance. Their habitation and economic development usually requires protection with dikes, quays, etc., which are effective in retaining floods but have the side effect of retarding sedimentation in their hinterlands. The flood-protected Dutch lowlands (so-called dike-ring areas) have been sediment-starved for up to about a millennium. In addition to this, peat decomposition and soil compaction, brought about by land drainage, have caused significant land subsidence. Sediment deficiency, defined as the combined effect of sediment-starvation and drainage-induced volume losses, has already been substantial in this area, and it is expected to become urgent in view of the forecasted effects of climate change (sea-level rise, intensified precipitation and run-off). We therefore explore this deficiency, compare it with natural (Holocene) and current human sediment inputs, and discuss it in terms of long-term land-use options. Materials and Methods: We use available 3D geological models to define natural sediment inputs to our study area. Recent progress in large-scale modelling of peat oxidation and compaction enables us to address volume loss associated with these processes. Human sediment inputs are based on published minerals statistics. All results are given as first-order approximations. Results: The current sediment deficit in the diked lowlands of the Netherlands is estimated at 136 ± 67 million m3/a. About 85% of this volume is the hypothetical amount of sediment required to keep up with sea-level rise, and 15% is the effect of land drainage (peat decomposition and compaction). The average Holocene sediment input to our study area (based on a total of 145 km3) is ~14 million m3/a, and the maximum (millennium-averaged) input ~26 million m3/a. Historical sediment deficiency has resulted in an unused sediment accommodation space of about 13.3 km3. Net human input of sediment material currently amounts to ~23 million m3/a. Discussion: As sedimentary processes in the Dutch lowlands have been retarded, the depositional system's natural resilience to sea-level rise is low, and all that is left to cope is human countermeasure. Preserving some sort of status quo with water management solutions may reach its limits in the foreseeable future. The most viable long-term solutions therefore seem a combination of allowing for more water in open country (anything from flood-buffer zones to open water) and raising lands that are to be built up (enabling their lasting protection). As to the latter, doubling or tripling the use of filling sand in a planned and sustained effort may resolve up to one half of the Dutch sediment deficiency problems in about a century. Conclusions: Conclusions, Recommendations and Perspectives. We conclude that sediment deficiency – past, present and future – challenges the sustainable habitation of the Dutch lowlands. In order to explore possible solutions, we recommend the development of long-term scenarios for the changing lowland physiography, that include the effects of Global Change, compensation measures, costs and benefits, and the implications for long-term land-use options. Recommendations and Perspectives: -     

Ascorbic acid oxidation in sucrose aqueous model systems at subzero temperatures

The reduction of Tempol by ascorbic acid in concentrated sucrose solutions was measured by electron paramagnetic resonance (EPR) at temperatures ranging from 16 to -16 degrees C. This method allowed the determination of the rate constants (k) of this fast reaction, by recording the Tempol reduction as a function of time. The two reactants were initially separated and had to migrate for the reaction to occur. The experimental findings were compared with predicted values according to the equation for diffusion-controlled reaction proposed by Atkins. The experimental reaction rate constants were observed to be lower than the calculated ones. However, the experimental values were found to be controlled by the temperature and viscosity changes of the reaction media, as expected for a diffusion-controlled reaction.     

Longitudinal trends in pH and aluminum chemistry of the Coxing Kill,Ulster County,New York

The purpose of this work was to characterize the Al chemistry along the longitudinal pH gradient of the Coxing Kill and thereby provide a basis for an in depth study of aluminum chemistry and transport as a function of pH. Water samples were collected along the pH gradient and analyzed for monomeric Al species, strong acid anions, base cations, ammonium, dissolved organic C and dissolved silica. Inorganic monomeric Al, organic momonmeric Al and dissolved organic C decreased in concentration as the stream's drainage area and pH increased. The ratio of organic to inorganic monomeric Al and the concentration of all other species increased with increasing pH. An abrupt change in stream chemistry occurred in conjunction with the gradual changes expected for a low order stream draining an acid sensitive watershed impacted by acid deposition. This abrupt change partially resulted from geological characteristics of the watershed.     

Thyroid Hormone Concentrations In Critically III Canine Intensive Care Patients

Alterations in thyroid indices in critically ill dogs were studied retrospectively to determine the incidence of the euthyroid sick syndrome and to assess its prognostic relevance to survival. Sixty-seven dogs were classified as euthyroid bases on a TSH stimulation test. Forty-one of 67 (61%) of the euthyroid dogs had low baseline serum T₄ concentrations (<1.5 ug/dl) and 38 of 67 (56%) of the euthyroid dogs had low baseline serum T₃ concentrations (<75 ng/dl). There was no significant difference between either the baseline or the post-stimulation serum T₄ concentrations when values of dogs that survived were compared with those that died. There was, however, a significant difference (P<0.05) between both the baseline and the post-stimulation values for T3 when survivors (100.3± 81 ng/dl, 143± 66 ng/dl) and non-survivors (64.2 ± 17.1 ng/dl, 96.6 ± 38.3 ng/dl) were compared. The euthyroid sick syndrome occurs commonly in critically ill dogs. Further, the extent of depression of serum concentrations of T₃ may be correlated to mortality.     

Validity of a health-related quality-of-life scale for dogs with signs of pain secondary to cancer

OBJECTIVE: To develop and validate a health-related quality-of-life scale for dogs with pain secondary to cancer. DESIGN: Questionnaire development. ANIMALS: 40 healthy dogs with no history or signs of pain, 20 dogs with dermatologic disease but no signs of pain other than mild pruritus, and 20 dogs with cancer. PROCEDURE: Owners of all dogs completed a questionnaire containing 12 questions with 4 options for each question, and a quality-of-life score ranging from 0 to 36 was calculated. Scores for dogs with cancer were compared with scores for healthy dogs and dogs with dermatologic disease. RESULTS: All owners indicated that the questionnaire was easy to complete. Scores for healthy dogs were significantly different from scores for dogs with cancer and scores for dogs with dermatologic disease. Scores for dogs with dermatologic disease were significantly different from scores for dogs with cancer. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that a simple questionnaire may be useful in assessing health-related quality of life in dogs with pain secondary to cancer, in that dogs with cancer had significantly lower scores than did healthy dogs and dogs with dermatologic disease.     

Use of multifrequency bioelectrical impedance analysis for estimation of total body water and extracellular and intracellular fluid volumes in horses

OBJECTIVE: To evaluate the use of multifrequency bioelectrical impedance analysis (MF-BIA) for estimating total body water (TBW), extracellular fluid volume (ECFV), and intracellular fluid volume (ICFV) in horses. ANIMALS: 9 healthy mares. PROCEDURE: TBW and ECFV were measured by use of deuterium oxide and sodium bromide dilution techniques, respectively. Intracellular fluid volume was calculated as the difference between TBW and ECFV. Concurrently, MF-BIA recordings were obtained by use of 4 anatomic electrode positions and 3 measurements of length. Models for MF-BIA data were created for all combinations of length and anatomic electrode position. Models were evaluated to determine the position-length configuration that provided the most consistent estimates of TBW, ECFV, and ICFV, compared with values determined by use of the dilution techniques. RESULTS: Positioning electrodes over the ipsilateral carpus and tarsus and use of height at the tuber sacrale for length provided the closest estimate between values for TBW, ECFV, and ICFV predicted by use of MF-BIA and measured values obtained by dilutional techniques. This model had the narrowest 95% limits of agreement. CONCLUSIONS AND CLINICAL RELEVANCE: MF-BIA techniques have been used to predict changes in TBW, ECFV, and ICFV in healthy and diseased humans. Results reported in this study provide an equine-specific model to serve as the basis for further evaluation of MF-BIA in horses with altered fluid states. The MF-BIA techniques have a number of potential applications for use in horses, including evaluation of exercise physiology, pharmacologic studies, and critical-care management.     

Use of the scrotum as a transposition flap for closure of surgical wounds in three dogs

OBJECTIVE: To describe use of the scrotum as a pedicle flap to cover defects created by tumor excision in the perineum or caudal and medial aspect of the thigh. STUDY DESIGN: Clinical study. ANIMALS: Three dogs. METHODS: After tumor excision and prescrotal castration, an incision was made around the base of the scrotum, leaving a pedicle on the side opposite the skin defect. After removal of the tunica dartos and abdominal fascia, the scrotal skin was stretched and shaped to the defect, then sutured in position with a simple interrupted pattern. Bandages that were changed every 48 hours compressed the flaps, and healing was observed until sutures were removed. RESULTS: Two dogs had first intention healing in 15 days, whereas 1 dog developed necrosis of 10% of the flap, and this area healed by second intention. CONCLUSION: In male dogs, the scrotal skin can be used as a pedicle flap for reconstructive surgery of wounds in the perineum and the proximomedial and caudal aspect of the thigh. CLINICAL RELEVANCE: The perineal region remains a surgical challenge because of the lack of the available skin for reconstruction of surgical wounds. The scrotal skin should be considered for use as a transposition flap to cover skin defects in this region.     

Hepatitis E viruses in humans and animals

Hepatitis E virus (HEV) is an emerging pathogen belonging to a newly recognized family of RNA viruses (Hepeviridae). HEV is an important enterically transmitted human pathogen with a worldwide distribution. It can cause sporadic cases as well as large epidemics of acute hepatitis. Epidemics are primarily waterborne in areas where water supplies are contaminated with HEV of human origin. There is increasing evidence, however, that many animal species are infected with an antigenically similar virus. A recently isolated swine virus is the best candidate for causing a zoonotic form of hepatitis E. The virus is serologically cross-reactive with human HEV and genetically very similar, and the human and swine strains seem to be cross-infective. Very recent evidence has also shown that swine HEV, and possibly a deer strain of HEV, can be transmitted to humans by consumption of contaminated meat. In this review, we discuss the prevalence, pathogenicity, diagnosis and control of human HEV, swine HEV, the related avian HEV and HEV in other hosts and potential reservoirs.