Body Heat Balance of a Man with Deficient Sweat Rate Subjected to Physical Work in a Hot Environment

The dynamics of physiological stress and thermal balance were investigated in men subjected to endogenous and exogenous heat loads. The study was conducted using the thermometric method. Substantial differences in the dynamics of the tested parameters and their quantitative characteristics were observed in 1 out of 8 participants. In this article, the observed differences are rationalized in terms of the deficient sweat rate mechanism. It is pointed out that it is indispensable to address these cases in work safety regulations.     

The Inversion Method in Measuring Noise Emitted by Machines in Opencast Mines of Rock Material

The inversion method was used to test vibroacoustic processes in large-size machines used in opencast mines of rock material. When this method is used, the tested machine is replaced with a set of substitute sources, whose acoustic parameters are determined on the basis of sound pressure levels and phase shift angles of acoustic signals, measured with an array of 24 microphones. This article presents test results of a combine unit comprising a crusher and a vibrating sieve, for which an acoustic model of 7 substitute sources was developed with the inversion method.     

Brainy stuff of long-gone dogs: a reappraisal of the supposed Canis endocranial cast from the Pliocene of Poland

The pre-Quaternary fossil record of Canis in the Old World is scarce, and the first appearance of this genus in Europe remains an enigma. Amongst the oldest fossils assigned to this genus, there is a natural cast of the brain (endocast) collected in W??e 1, Poland, from Pliocene deposits dated between 3.3 and 4.0 Ma. We reexamined this specimen and found that it differs from the brain of Canis in having its region medial to the coronal sulcus heart-shaped in dorsal view, its region rostral to the presylvian sulcus shorter and less constricted laterally, and its cerebellum less overlapped by the cerebrum and lacking a lateral twist of the posterior vermis. We identified this fossil, as well as another fossil canid endocast from W??e 1, as representing the raccoon dog genus Nyctereutes. The previously reported presence of Canis in W??e 1 is therefore not confirmed. Specifically, both endocasts can be referred to N. donnezani because this is the only species of Nyctereutes that has been recognised in this locality on the basis of craniomandibular and dental fossils. Our study represents a taxonomic application of comparative neuroanatomical and palaeoneurological data, an approach that may become increasingly useful with the growing knowledge of the endocranial morphology of fossil mammals.     

Workstations for people with disabilities: an example of a virtual reality approach

This article describes a method of adapting workstations for workers with motion disability using computer simulation and virtual reality (VR) techniques. A workstation for grinding spring faces was used as an example. It was adjusted for two people with a disabled right upper extremity. The study had two stages. In the first, a computer human model with a visualization of maximal arm reach and preferred workspace was used to develop a preliminary modification of a virtual workstation. In the second stage, an immersive VR environment was used to assess the virtual workstation and to add further modifications. All modifications were assessed by measuring the efficiency of work and the number of movements involved. The results of the study showed that a computer simulation could be used to determine whether a worker with a disability could access all important areas of a workstation and to propose necessary modifications.     

Influence of the milling tool setup on occupational safety in furniture making

One of the most serious causes of accidents in furniture making is kickback of machined material. The aim of this study was to determine the influence of the milling tool setup on hazards associated with kickback in furniture making. The speed of kickback was accepted as the measure of these hazards. The experiment involved controlled changes in milling tool setup, projection of cutting knives over the body of the milling tool, number of cutting knives and clearance angle. Multifactor analysis of variance was applied to the results of individual experiments, showing statistically significant factors and their interactions. Inspection and analysis of traces left by the cutting knives of the tools on the test pieces made of wood materials supported inferential statistics. The obtained results verified some common opinions and ideas on the impact of the milling tool setup on the hazards resulting from kickback in furniture making.     

Evaluation of a new ballistic vest design for compliance with Standard No. PN-V-87000:2011 using physiological tests

Research into newly developed ballistic vests to be worn by police officers under clothing was carried out with air temperature conditions of +20 °C. A ballistic vest should incorporate protective features, comfort and ergonomics. The thermal strain on users who wore the vests was evaluated as an average and individually, after they had been conditioned in high (+50 °C), low (?40 °C) or neutral (+20 °C) air temperatures, while performing various occupational activities. Research involved six police officers aged 36–42 years, who wore civilian clothing used in moderate environmental conditions. During the tests, physiological parameters (internal temperature, local skin temperatures and amount of sweat secreted) were determined. The ease of doing exercises while wearing the vests, vest service and level of discomfort in use were assessed. Research showed that the vests tested, both as an average and individually, meet the requirements of Standard No. PN-V-87000:2011 (clause 4.5).     

A study of mechanisms responsible for incorporation of cesium and radiocesium into fruitbodies of king oyster mushroom (Pleurotus eryngii)

Ex vitro cultures of Pleurotus eryngii were carried out under controlled conditions using sterile medium composed of barley seeds. The influence of alkali and alkaline earth element salts (CsCl, KCl, NaCl, RbCl, and CaCl(2)) and tetraethylammonium chloride on incorporation of cesium, potassium, sodium, rubidium and calcium, and their distribution within fruitbodies, was examined. The results show that incorporation of cesium into fruitbodies was not suppressed by Na(+) and Rb(+) or tetraethylammonium chloride. However, it was inhibited by Ca(2+) and stimulated by high concentrations of K(+). The inhibition of cesium incorporation by Ca(2+), lack of influence of tetraethylammonium chloride and stimulation by high K(+) concentrations suggest that there may exist two pathways of passive transport of cesium in mycelium: (i) uptake mediated by a non-specific potassium channel localised in plasmalemma (similar to voltage-insensitive cation channel, VICC) followed by diffusive transport inside hyphae and (ii) extracellular transport from the medium through inter-hyphal cavities into fruitbodies. The results highlight distinctiveness of mechanisms responsible for the uptake and incorporation of cesium in mushrooms and plants.     

Distribution of metals (Fe, Mn, Zn, Cu) in fish tissues in two lakes of different trophy in Northwestern Poland

This study presents concentrations of iron, manganese, zinc, and copper in selected tissues of two fish species: pike (Esox lucius L.) and bream (Abramis brama L.) living in lakes Ińsko and Wisola, Northwestern Poland. The lakes differ in their trophic status. The effect of gender and environmental conditions on metals accumulation was also investigated. Metal analyses were performed using inductively coupled plasma atomic emission spectroscopy. Considering all studied fish species and tissues, the average metal concentrations (micrograms per gram wet weight) in both lakes occurred in the following ranges: Fe 0.8–240.6, Mn 0.2–8.4, Zn 3.0–185.9, and Cu 0.14–7.76. The lowest levels of the studied metals were always detected in the muscles. The spleen, kidneys, and liver were found to accumulate the highest amounts of Fe. In the case of the other metals, the highest levels were found, as follows: Mn in skin, gills, and gonads, Zn in digestive tract and gills, Cu in liver. Heavy metal content in fish gonads was observed to be sex dependent.