Selection of line-transect methods for estimating the density of group-living animals: lessons from the primates

We review the four major contemporary methods for estimating density of group-living animals from line-transect sampling: perpendicular modelling of group centers, perpendicular modelling of center of measurable individuals, strip transects and animal-observer distance. The efficacy of each method is evaluated to produce a simple selection guide. We review the literature and use field data from the Udzungwa Mountains, Tanzania. The review is relevant to all group-living animals; however, examples are drawn from the primates. Perpendicular methods have better mathematical justification than non-perpendicular methods. For perpendicular methods using detection function models, it is preferable to measure group location using center of measurable individuals, as group centers are hard to estimate. The assumptions of detection function models are often broken in poor visibility habitats or with unhabituated animals. Alternatively strip transects may be used where there are reliable data on group spread and/or visibility. Strip transects are also the most practical, along with the animal-observer method; however, the latter lacks mathematical justification. We conclude that there are arguments for continued use of all four methods. In certain situations the use of raw encounter rates may also be considered. The appropriate method is determined by minimizing bias and considering time, resources and field conditions.     

Will Agroforests Vanish? The Case of Damar Agroforests in Indonesia

Resin producing agroforestry in the Krui area of Sumatra in Indonesia is presented as an environmentally friendly, income generating land-use system which contributes to both development and conservation objectives. We studied the change in household income portfolios in three communities in the Krui area. The studies revealed that in the period 1995–2004 agroforestry remained the main source of income. We predict, however, that due to declining resin productivity per hectare, and rising price and demand for timber, an increasing number of farmers will cut their mature agroforests in the near future. At the same time our data suggests that farmers will continue tree planting activities. In result old agroforests may vanish while new ones will be established.

Capture and medetomidine-ketamine anesthesia of free-ranging wolverines (Gulo gulo)

Capture and anesthesia with medetomidine-ketamine were evaluated in free-ranging wolverines (Gulo gulo) immobilized for marking with radiocollars or intraperitoneal radiotransmitters in Norrbotten, Sweden, during early June 2004 and 2005. Twelve juvenile wolverines were captured by hand and injected with 0.14 +/- 0.03 mg/kg (mean +/- SD) medetomidine and 7.5 +/- 2.0 mg/kg ketamine. Twelve adult wolverines were darted from a helicopter or the ground, or captured by hand. Adults received 0.37 +/- 0.06 mg/kg medetomidine and 9.4 +/- 1.4 mg/kg ketamine. Arterial blood samples were collected between 15 min and 30 min and between 45 min and 60 min after drug administration and immediately analyzed for selected hematologic and plasma variables. Hyperthermia was recorded initially in one juvenile wolverine and 11 adults. Rectal temperature, heart rate, and lactate decreased significantly during anesthesia, whereas hemoglobin oxygen saturation, pH, partial pressure of arterial carbon dioxide, and base excess increased. Adult wolverines darted from a helicopter had a significantly higher rectal temperature, higher glucose and hematocrit values, and a lower heart rate than juveniles captured by hand. Impaired arterial oxygenation was evident in all wolverines. This study provides baseline data on physiologic variables in adult and juvenile wolverines captured with different methods and anesthetized with medetomidine-ketamine.     

HIV envelope-CXCR4 signaling activates cofilin to overcome cortical actin restriction in resting CD4 T cells

Binding of the HIV envelope to the chemokine coreceptors triggers membrane fusion and signal transduction. The fusion process has been well characterized, yet the role of coreceptor signaling remains elusive. Here, we describe a critical function of the chemokine coreceptor signaling in facilitating HIV infection of resting CD4 T cells. We find that static cortical actin in resting T cells represents a restriction and that HIV utilizes the Galphai-dependent signaling from the chemokine coreceptor CXCR4 to activate a cellular actin-depolymerizing factor, cofilin, to overcome this restriction. HIV envelope-mediated cofilin activation and actin dynamics are important for a postentry process that leads to viral nuclear localization. Inhibition of HIV-mediated actin rearrangement markedly diminishes viral latent infection of resting T cells. Conversely, induction of active cofilin greatly facilitates it. These findings shed light on viral exploitation of cellular machinery in resting T cells, where chemokine receptor signaling becomes obligatory.     

<Emphasis Type="Italic">Batrachochytrium</Emphasis><Emphasis Type="Italic">dendrobatidis</Emphasis> and Chytridiomycosis in Anuran Amphibians of Colombia

In order to investigate the possible presence of the chytrid fungus Batrachochytrium dendrobatidis (Chytridiomycota: Chytridiales) in frogs (Amphibia: Anura) of Colombia, we made a retrospective examination of formalin-fixed specimens preserved in natural history collections. Using the staining technique of hematoxylin and eosin to identify B. dendrobatidis in histological slices, we found evidence of the fungus in 3 of the 53 frog species examined from a total of 672 specimens collected in 17 departments within Colombia between 1968 and 2006. The infected specimens were found dead or dying in recent years in high elevation sites, suggesting that chytridiomycosis (the disease caused by the fungus) may represent a significant threat to Colombian amphibians. We conclude that a more extensive search for B. dendrobatidis in museum specimens and wild-caught frogs should be undertaken as soon as possible, using both histological and molecular genetic techniques, in order to further characterize the geographic and taxonomic extent of infections of B. dendrobatidis.     

Synthesis of Polycyclic Aromatic Hydrocarbons and Acetylene Polymers in Ice: A Prebiotic Scenario

The recent evidences of presence of subsurface oceans of liquid water and ice on Saturn's moons, and the possible presence and astrobiological importance of polycyclic aromatic hydrocarbons (PAHs) in these environments, provide strong motivation for the exploration of the prebiotic chemistry in ice and to test if PAHs could be experimentally synthesized in ice surfaces under atmospheres containing methane as carbon source. In this work, we present a new design for prebiotic‐chemistry experiments in ice matrix. Using this design, a mixture of products including PAHs, polar aromatic compounds, and hydrophilic acetylene‐based polymers was obtained. We propose that acetylene generation in a methane/nitrogen atmosphere and subsequent polymerization to PAHs and polyynes could be a favored pathway in the presence of water freeze–melt cycles. These results shed light on the processes involved in PAH synthesis in icy environments and on the physical factors that drive the different competing pathways in methane/nitrogen atmospheres.     

Clinical outcome in chronic myeloid leukemia after allogeneic hematopoietic stem cell transplantation: the experience of the Bone Marrow Transplantation Unit of FUNFARME/BRAZIL using FISH

Investigation of the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in chronic myeloid leukemia patients is essential to predict prognosis and survival. In 20 patients treated at the Bone Marrow Transplantation Unit of S?o José do Rio Preto (S?o Paulo, Brazil), we used fluorescence in situ hybridization (FISH) to investigate the frequency of cells with BCR/ABL rearrangement at diagnosis and at distinct intervals after allo-HSCT until complete cytogenetic remission (CCR). We investigated the disease-free survival, overall survival in 3 years and transplant-related mortality rates, too. Bone marrow samples were collected at 1, 2, 3, 4, 6, 12, and 24 months after transplantation and additional intervals as necessary. Success rate of the FISH analyses was 100%. CCR was achieved in 75% of the patients, within on average of 3.9 months; 45% patients showed CCR within 60 days after HSCT. After 3 years of the allo-HSCT, overall survival rate was 60%, disease-free survival was 50% and the transplant-related mortality rate was 40%. The study demonstrated that the BCR-ABL FISH assay is useful for follow-up of chronic myeloid leukemia patients after HSCT and that the clinical outcome parameters in our patient cohort were similar to those described for other bone marrow transplantation units.     

A high-throughput fluorescence-based glycosyltransferase screen and its application in directed evolution

This protocol details the application of a high-throughput fluorescence-based screen, in conjunction with error-prone PCR/saturation mutagenesis, for altering the proficiency and/or promiscuity of a secondary metabolite glycosyltransferase (GT) via directed evolution. Given the structural and mechanistic similarities among secondary metabolite-associated GTs, this approach may provide a template for engineering other members of the GT-B superfamily.     

A novel role for PECAM-1 (CD31) in regulating haematopoietic progenitor cell compartmentalization between the peripheral blood and bone marrow

Although the expression of PECAM-1 (CD31) on vascular and haematopoietic cells within the bone marrow microenvironment has been recognized for some time, its physiological role within this niche remains unexplored. In this study we show that PECAM-1 influences steady state hematopoietic stem cell (HSC) progenitor numbers in the peripheral blood but not the bone marrow compartment. PECAM-1(-/-) mice have higher levels of HSC progenitors in the blood compared to their littermate controls. We show that PECAM-1 is required on both progenitors and bone marrow vascular cells in order for efficient transition between the blood and bone marrow to occur. We have identified key roles for PECAM-1 in both the regulation of HSC migration to the chemokine CXCL12, as well as maintaining levels of the matrix degrading enzyme MMP-9 in the bone marrow vascular niche. Using intravital microscopy and adoptive transfer of either wild type (WT) or PECAM-1(-/-) bone marrow precursors, we demonstrate that the increase in HSC progenitors in the blood is due in part to a reduced ability to migrate from blood to the bone marrow vascular niche. These findings suggest a novel role for PECAM-1 as a regulator of resting homeostatic progenitor cell numbers in the blood.