Probing the limits of tool competence: experiments with two non-tool-using species (Cercopithecus aethiops and Saguinus oedipus).

Non-human animals vary in their ability to make and use tools. The goal of the present study was to further explore what, if anything, differs between tool-users and non-tool-users, and whether these differences lie in the conceptual or motor domain. We tested two species that typically do not use tools-cotton top tamarins (Saguinus oedipus) and vervet monkeys (Cercopithecus aethiops)-on problems that mirrored those designed for prolific tool users such as chimpanzees.

A central role for ROS in the functional remodelling of L-type Ca2+ channels by hypoxia.

Periods of prolonged hypoxia are associated clinically with an increased incidence of dementia, the most common form of which is Alzheimer's disease. Here, we review recent studies aimed at providing a cellular basis for this association. Hypoxia promoted an enhanced secretory response of excitable cells via formation of a novel Ca2+ influx pathway associated with the formation of amyloid peptides of Alzheimer's disease.

Amyloid beta peptide as a physiological modulator of neuronal 'A'-type K+ current.

Control of neuronal spiking patterns resides, in part, in the type and degree of expression of voltage-gated K(+) channel subunits. Previous studies have revealed that soluble forms of the Alzheimer's disease associated amyloid beta protein (Abeta) can increase the 'A'-type current in neurones. In this study, we define the molecular basis for this increase and show that endogenous production of Abeta is important in the modulation of Kv4.

Hypoxia stimulates Ca2+ release from intracellular stores in astrocytes via cyclic ADP ribose-mediated activation of ryanodine receptors.

The ability of O(2) levels to regulate Ca(2+) signalling in non-excitable cells is poorly understood, yet crucial to our understanding of Ca(2+)-dependent cell functions in physiological and pathological situations. Here, we demonstrate that hypoxia mobilizes Ca(2+) from an intracellular pool in primary cultures of cortical astrocytes. This pool can also be mobilized by bradykinin, which acts via phospholipase C and inositol trisphosphate production.

Determination of the sedimentation constants for total suspended solids and the algal component in a full-scale primary facultative pond operating at high wind velocities under tropical conditions.

This study evaluated the amount, distribution and sedimentation constant of solids in a full-scale primary facultative pond operating mostly under high wind conditions and the contribution made by the algal biomass. Solids deposition rates were measured using sedimentation traps placed in the inlet and outlet zones of the pond. Most sludge accumulation occurred, not surprisingly, in the inlet zone A1 with a sludge volume of 9072.

Variations in BOD, algal biomass and organic matter biodegradation constants in a wind-mixed tropical facultative waste stabilization pond.

This study considered the impact of wind mixing on the efficiency of BOD removal and the first order biodegradation constant for organic matter in a primary facultative pond. Wind speeds of 1-4 m/s blowing from the effluent end of the pond towards the influent created surface-water flows of up to 0.94 m/s as determined by orange and coconut drogues moving in the opposite direction to the bulk hydraulic flow of 0.

Implications for physical design: The effect of depth on the performance of waste stabilization ponds.

Studies on experimental primary facultative ponds showed that varying the depth from 1.25 m to 2.3 m had no effect on the rates of BOD removal.

Poor knowledge regarding the Pap test among low-income women undergoing routine screening.

Context: Many women undergoing cervical cancer screening lack appropriate understanding of the Pap test. It is important to evaluate knowledge and informational needs about Pap testing among groups who may have difficulty accessing care or a relatively low likelihood of obtaining follow-up for an abnormal result, such as minority and low-income women.

Methods: A sample of 338 women undergoing cervical screening at two clinics in Texas completed a questionnaire measuring their knowledge of Pap testing and asking what specific information they would like to know about the test.

In-continuity hepatic resection for advanced hilar cholangiocarcinoma.

Background: The purpose of this study was to examine outcomes of patients undergoing concomitant hepatectomy and bile duct excision for advanced Klatskin tumors.

Methods: Thirty-one patients, 16 men and 15 women, with an average age of 64 years, underwent concomitant biliary and hepatic resections for Klatskin tumors. Outcomes, including complications and survival, are reported.

N-ViroTech--a novel process for the treatment of nutrient limited wastewaters.

As pulp and paper wastewaters are mostly deficient in nitrogen and phosphorus, historical practice has dictated that they cannot be effectively treated using microbiological processes without the addition of supplementary nutrients, such as urea and phosphoric acid. Supplementation is a difficult step to manage efficiently, requiring extensive post-treatment monitoring and some degree of overdosing to ensure sufficient nutrient availability under all conditions. As a result, treated wastewaters usually contain excess amounts of both nutrients, leading to potential impacts on the receiving waters such as eutrophication.

Hypoxic regulation of Ca2+ signaling in cultured rat astrocytes.

Acute hypoxia modulates various cell processes, such as cell excitability, through the regulation of ion channel activity. Given the central role of Ca2+ signaling in the physiological functioning of astrocytes, we have investigated how acute hypoxia regulates such signaling, and compared results with those evoked by bradykinin (BK), an agonist whose ability to liberate Ca2+ from intracellular stores is well documented. In Ca2+-free perfusate, BK evoked rises of [Ca2+]i in all cells examined.