The feeding ecology and activity budget of proboscis monkeys

A group of proboscis monkeys (Nasalis larvatus) consisting of an alpha‐male, six adult females, and several immatures was observed from May 2005–2006. We collected over 1,968 hr of focal data on the adult male and 1,539 hr of focal data on the six females in a forest along the Menanggul River, Sabah, Malaysia. Availability and seasonal changes in plant species consumed by the focal monkeys were determined by vegetation surveys carried out across an area of 2.15 ha along 200–500 m trails in riverine forest. A total of 188 plant species were consumed by the focal monkeys. The activity budget of members of our study group was 76.5% resting, 19.5% feeding, and 3.5% moving. Young leaves (65.9%) and fruits (25.9%) accounted for the majority of feeding time. Over 90% of fruit feeding involved the consumption of unripe fruits and in the majority of case both the fruit flesh and seeds were eaten. Although fruit eating was rare in some months, during other times of the year time fruit feeding exceeded the time devoted to young leaves. We found that monthly fruit availability was positively related to monthly fruit eating and feeding activity, and seasonal fluctuations in dietary diversity were significantly affected by fruit eating. These results suggest that fruit availability and fruit‐eating behaviors are key factors that influence the activity budget of proboscis monkeys. Earlier assumptions that colobine monkeys are obligate folivores do not apply well to proboscis monkeys and certain other colobines. Our findings may help contribute to a better understanding of the dietary adaptations and feeding ecology of Asian colobines. Am. J. Primatol. 71:478–492, 2009. © 2009 Wiley‐Liss, Inc.     

Clouded leopard (<Emphasis Type="Italic">Neofelis diardi</Emphasis>) predation on proboscis monkeys (<Emphasis Type="Italic">Nasalis larvatus</Emphasis>) in Sabah,Malaysia

In this study, we have reported two direct observations of individuals from a one-male group of proboscis monkeys (Nasalis larvatus) being killed by clouded leopards (Neofelis diardi) in the riverine forest along the Menanggul river, a tributary of the Kinabatangan river in Sabah, Malaysia. One of the two individuals was an infant female and the other was a juvenile female. Based on literature reviews and the observations reported here, we suggest that clouded leopard and crocodile might be significant potential predators of proboscis monkeys of any age or sex and that predation threats elicit the monkeys' anti-predator strategies. Moreover, the observations of the monkeys' behaviour when the group is attacked by a predator suggest that the adult males in one-male groups play an important role as protectors.     

Molecular and cellular detection of expression of vitellogenin and <Emphasis Type="Italic">zona radiata</Emphasis> protein in liver and skin of juvenile salmon (<Emphasis Type="Italic">Salmo salar</Emphasis>) exposed to nonylphenol

In developing bioassays for estrogenic effects, vitellogenin (Vtg) induction and zona radiata protein (Zr-protein) induction in males and juveniles of oviparous vertebrates have been used as sensitive biomarkers for estrogenicity. Nonylphenol (NP) produces similar and parallel expression patterns of Vtg and Zr-protein levels in plasma and surface mucus of salmon, the response being concentration- and time-dependent. We have explored the potential mechanisms of Vtg and Zr-protein expression in surface mucus by comparative molecular and cellular approaches. Liver, skin, blood, and surface mucus samples were collected from fish exposed to a single waterborne concentration of NP (10 and 60 μg/l), 3, 7, and 10 days post-exposure, for gene expression analysis (liver and skin; quantitative real-time polymerase chain reaction) and protein analysis (blood and surface mucus; enzyme-linked immunosorbent assay). Protein expression was localized by immunohistochemistry. NP produced concentration- and time-dependent increases of hepatic estrogen receptors (ERα and ERβ), Vtg, and Zr-protein mRNA and plasma protein levels. These responses paralleled cellular detection of Vtg and Zr-protein in the liver with unique expression patterns in the cytoplasm of hepatocytes, hepatic sinusoids, and endothelial cells. ERα, Vtg, and Zr-protein mRNA were detectable in the skin. ERβ was the only skin response that was NP-concentration-dependent, especially at day 10 post-exposure. Immunohistochemistry for Vtg and Zr-protein in skin showed unique expression patterns in mucus vacuoles, epidermal cells, and scales in an NP-concentration- and time-specific manner. Thus, analysis of skin mRNA levels for xenoestrogen biomarker responses is a less-promising approach than protein analysis. The immunohistochemical localization of Vtg and Zr-protein levels in the skin further validates surface mucus as a sensitive biomarker source for estrogenic compounds. These responses represent an improvement for the detection of endocrine-disrupting compounds and related pollutants in the environment. The Norwegian Research Council (NFR) financially supported this study.     

The effects of timing of N application and plant growth regulators on morphogenesis and yield formation in wheat

The influence of timing of N application and PGRs on wheat morphogenesisand yield formation was studied under non-lodging condition. N treatmentsconsisted of three different proportions applied at sowing, 3-leaf stage, stemelongation stage and booting stage, respectively. PGR treatments were 30ppm uniconazole (S₃₃₀₇), 30 ppmgibberellicacid (GA₃) and a mixture of S₃₃₀₇ and GA₃.S₃₃₀₇ increased tillering, but had no obvious effect on the finalnumber of ears per plant. The combined application of S₃₃₀₇ andGA₃increased ears per plant. S₃₃₀₇ significantly reducedplant height and the length of two basal internodes, the area of two topmostleaves, number of florets per spike, shoot and grain weight per plant in all Ntreatments, particularly in N treatment 6040 (see below), but increased dryweight per unit length of two basal internodes. It is suggested thatapplicationof plant growth retardant such as S₃₃₀₇ may reduce grain yield byinhibiting formation and development of both source (leaf area) and sink(floret) under little or no lodging condition. When applied together,GA₃ modified some inhibition of growth by S₃₃₀₇. Thetiming of N application had significant influence on most of the charactersstudied. The N treatment 6040, in which 60% of total N fertiliser wasapplied at sowing and 40% at stem elongation, produced the greatest earnumber per plant, florets and grains per ear, the largest area of the twotopmost leaves, and the highest grain yield, indicating that more N applicationat stem elongation was favourable to high yield formation.     

Herders' Perceptions, Practice, and Problems of Night Grazing in the Sahel: Case Studies from Niger

A survey was conducted from February to June of 1997 among livestock herders in two villages of Niger, Kodey and Toukounous, on their perceptions, practice, and problems of night grazing. Cattle and sheep were the species that were taken out for night grazing by the herders. Small herd size and labor constraints were mentioned as the principal reasons for not practicing night grazing. Major benefits of night grazing included good body condition, herd growth, increased milk production, prevention of diseases, and reduction in herd mortality. Insecurity, difficulty in staying awake at night, labor constraints, and damage to crops by animals were given as problems of night grazing. According to the herders, grazing time (duration) during the day and night was shorter in the wet season than in the dry season. In the wet season animals were herded (followed and closely supervised by herders), whereas in the dry season, animals were mostly left to range freely in both villages. In general, children herded the animals during the day, while adults were responsible for night-time herding. Herders' perceptions on night grazing as regards animal production parameters such as weight development, water consumption, fecal output and feeding behavior are consistent with available experimental results. Therefore, future technical research needs to recognize the constraints faced by herders and determine how to overcome them to improve technical and economic efficiency.     

Engineered early embryonic cardiac tissue retains proliferative and contractile properties of developing embryonic myocardium

Embryonic myocardium has a high rate of cell proliferation and regulates cellular proliferation, contractile function, and myocardial architecture in response to changes in external mechanical loads. However, the small and complex three-dimensional (3D) structure of the embryonic myocardium limits our ability to directly investigate detailed relationships between mechanical load, contractile function, and cardiomyocyte proliferation. We developed a novel 3D engineered early embryonic cardiac tissue (EEECT) from early embryonic ventricular cells to test the hypothesis that EEECT retains the proliferative and contractile properties of embryonic myocardium. We combined freshly isolated White Leghorn chicken embryonic ventricular cells at Hamburger-Hamilton (HH) stage 31 (day 7 of a 46-stage, 21-day incubation period), collagen type I, and matrix factors to construct cylindrical-shaped EEECTs. We studied tissue architecture, cell proliferation patterns, and contractile function. We then generated engineered fetal cardiac tissue (EFCT) from HH stage 40 (day 14) fetal ventricular cells for direct comparison with EEECT. Tissue architecture was similar in EEECT and EFCT. EEECT maintained high cell proliferation patterns by culture day 12, whereas EFCT decreased cell proliferation rate by culture day 9 (P < 0.05). EEECT increased active contractile force from culture day 7 to day 12. The culture day 12 EEECT contractile response to the beta-adrenergic stimulation was less than culture day 9 EFCT (P < 0.05). Cyclic mechanical stretch stimulation induced myocardial hyperplasia in EEECT. Results indicate that EEECT retains the proliferative and contractile properties of developing embryonic myocardium and shows potential as a robust in vitro model of developing embryonic myocardium.     

Hepatic biotransformation responses in Atlantic salmon exposed to retinoic acids and 3,3',4,4'-tetrachlorobiphenyl (PCB congener 77)

Active derivatives of vitamin A are essential in physiological processes such as cell growth, differentiation, morphogenesis and development. The biological functions of vitamin A are mediated through the retinoid acid receptors (RARs) and retinoid X receptors (RXRs). Aryl hydrocarbon receptor (AhR) agonists such as planar halogenated compounds are known to interfere with vitamin A homeostasis in both field and laboratory studies. In this study, we have investigated the molecular interactions between vitamin A and AhR signalling pathways using juvenile Atlantic salmon and agonists for both receptor pathways. Groups of juvenile salmon were treated with all-trans- and 9-cis-retinoic acid mixture (7:3 ratio) dissolved in DMSO (dimethyl sulfoxide) at 0.1, 1 and 10 mg/kg fish weight. The mixture was force fed singly or in combination with 0.1 mg 3,3',4,4'-tetrachlorobiphenyl (co-planar congener 77)/kg fish weight dissolved in DMSO. Liver samples were collected 3 days after PCB-77 exposure. A separate group exposed to combined retinoic acid (1 mg/kg for 5 days) and PCB-77, was sampled at 3, 7 and 14 days after PCB-77 exposure. Liver samples collected from all exposure groups were analyzed for gene (RARalpha, AhR2alpha, AhR2beta, CYP1A1, UGT1 and GSTpi) expression using real-time PCR and activity (7-ethoxyresorufin O-deethylase (EROD), UGT and GST) using biochemical methods with specific substrates. Our data showed that exposure to RA alone did not produce a significant increase of RARalpha mRNA levels, and the presence of PCB-77 attenuated the expression of RARalpha in RA dose- and time-specific manner. In addition, RA produced a dose-dependent increase of CYP1A1 mRNA and activity (EROD) levels without concomitant increase in AhR2 isoforms. When administered alone, PCB-77 produced increased CYP1A1, UGT1 and GSTpi mRNA and enzyme levels. The PCB-77-induced CYP1A1, UGT1 and GSTpi (mRNA and activity) levels were modulated by RA, in a parameter and dose-specific manner. In general, our data show an interaction between vitamin A and AhR signalling that may affect retinoid homeostasis in fish.     

Calcium channel modulation as an all-purpose mechanism for short-term synaptic plasticity

The paper by Mochida et al. in this issue of Neuron proposes that synaptic facilitation, depression, and augmentation all arise from calcium-dependent regulation of calcium channels in the presynaptic terminal. Their proposal provides a unifying explanation for several forms of short-term presynaptic plasticity.