Impaired Auditory Temporal Selectivity in the Inferior Colliculus of Aged Mongolian Gerbils

Aged humans show severe difficulties in temporal auditory processing tasks (e.g., speech recognition in noise, low-frequency sound localization, gap detection). A degradation of auditory function with age is also evident in experimental animals. To investigate age-related changes in temporal processing, we compared extracellular responses to temporally variable pulse trains and human speech in the inferior colliculus of young adult (3 month) and aged (3 years) Mongolian gerbils. We observed a significant decrease of selectivity to the pulse trains in neuronal responses from aged animals. This decrease in selectivity led, on the population level, to an increase in signal correlations and therefore a decrease in heterogeneity of temporal receptive fields and a decreased efficiency in encoding of speech signals. A decrease in selectivity to temporal modulations is consistent with a downregulation of the inhibitory transmitter system in aged animals. These alterations in temporal processing could underlie declines in the aging auditory system, which are unrelated to peripheral hearing loss. These declines cannot be compensated by traditional hearing aids (that rely on amplification of sound) but may rather require pharmacological treatment

A solution to the subdiffusion-efficiency paradox: Inactive states enhance reaction efficiency at subdiffusion conditions in living cells

Macromolecular crowding in living biological cells effects subdiffusion of larger biomolecules such as proteins and enzymes. Mimicking this subdiffusion in terms of random walks on a critical percolation cluster, we here present a case study of EcoRV restriction enzymes involved in vital cellular defence. We show that due to its so far elusive propensity to an inactive state the enzyme avoids non-specific binding and remains well-distributed in the bulk cytoplasm of the cell. Despite the reduced volume exploration capability of subdiffusion processes, this mechanism guarantees a high efficiency of the enzyme. By variation of the non-specific binding constant and the bond occupation probability on the percolation network, we demonstrate that reduced non-specific binding are beneficial for efficient subdiffusive enzyme activity even in relatively small bacteria cells. Our results corroborate a more local picture of cellular regulation.Comment: 6 plus epsilon pages, 6 figure

Triadimefon ameliorates negative effects of in vitro salt stress on two cultivars of alfalfa(Medicago sativa L.)

Triadimefon (TRD) is a member of triazol plant growth regulator group which is responsible for increasing stress tolerance. Effects of TRD on two cultivars of Medicago sativa (Hamedani and Yazdi) were investigated. The in vitro grown plantlets in MS medium were cultured in TRD at concentration 1.0, 2.0 and 4.0 mg/l combined with 0, 100 and 140 mM NaCl respectively. The changes in growth parameters, photosynthetic pigment, carbohydrate, α-tochopherol, glycine betain, proline and proline dehydrogenase (PDH) activity as well as its expression were measured after four weeks post treatment. NaCl treatment decreased overall plant growth and reduced the total chlorophyll, carbohydrate content, PDH activity and increased α-tochopherol, glycine betain content and proline content. The level of PDH transcript was changed in different combinations of NaCl and TRD, however, at 140 mM NaCl and 2 mg/l TRD expression was decreased. When plants were subjected to salt stress, TRD minimized the inhibitory effects of NaCl on plant growth by increasing, total chlorophyll, carbohydrate, α-tochopherol, glycine betaine content

Development of the Metal Rheology Model of High-temperature Deformation for Modeling by Finite Element Method

It is shown that when modeling the processes of forging and stamping, it is necessary to take into account not only the hardening of the material, but also softening, which occurs during hot processing. Otherwise, the power parameters of the deformation processes are precisely determined, which leads to the choice of more powerful equipment. Softening accounting (processes of stress relaxation) will allow to accurately determine the stress and strain state (SSS) of the workpiece, as well as the power parameters of the processes of deformation. This will expand the technological capabilities of these processes. Existing commercial software systems for modeling hot plastic deformations based on the finite element method (FEM) do not allow this. This is due to the absence in these software products of the communication model of the component deformation rates and stresses, which would take into account stress relaxation. As a result, on the basis of the Maxwell visco-elastic model, a relationship is established between deformation rates and stresses. The developed model allows to take into account the metal softening during a pause after hot deformation. The resulting mathematical model is tested by experiment on different steels at different temperatures of deformation. The process of steels softening is determined using plastometers. It is established experimentally that the model developed by 89 ... 93 % describes the rheology of the metal during hot deformation. The relationship between the components of the deformation rates and stresses is established, which allows to obtain a direct numerical solution of plastic deformation problems without FED iterative procedures, taking into account the real properties of the metal during deformation. As a result, the number of iterations and calculations has significantly decreased

Lived Experiences of Temporary Permanence: The Syrian Perspective on Humanitarian Response and ‘Guest Status’ in Jordan

As the conflict in Syria has evolved into a long-term crisis, Syrian refugees have found themselves in a state of both temporality and permanence, frequently cited as being ‘stuck’. Syrians in Jordan, particularly, have fallen victim to this status, frequently labeled as ‘guests’, with corresponding humanitarian aid also reflecting this temporality. No studies have yet explored Syrian refugees perceptions and experiences with ‘guest’ status and its relationship with humanitarian assistance. The purpose of this study is to explore Syrian perception of ‘guest’ status and current humanitarian efforts in Jordan and see how this demonstrates and challenges the dichotomy present in Syrian refugee status of simultaneous temporality and permanence. Through ten semi-structured interviews with Syrians, followed by a thematic and inductive analysis, the data revealed six themes. Themes included the influence of gender on assistance, perceived lack of transparency from humanitarian organizations, impaired social interaction, instability of resources, shifting perspectives regarding ‘guest’ status, and future uncertainty. Additionally, narratives reveal a relationship between humanitarian assistance and Syrian status as aid has decreased due to perceived ‘temporal’ status, despite the elongated length of the conflict. All Syrian participants have no intention of returning to Syria in the foreseeable future, and despite many having been in Jordan for more than six years, this idea of finding stability and permanence is challenged by both physical and mental challenges associated with current unstable assistance and perceived status that have made Syrians simultaneously feel as if their lives in Jordan are temporal. This study works to shed light on the lived experiences frequently forgotten but just as powerful as policy assessment

The hippocampus, prefrontal cortex, and perirhinal cortex are critical to incidental order memory.

Considerable research in rodents and humans indicates the hippocampus and prefrontal cortex are essential for remembering temporal relationships among stimuli, and accumulating evidence suggests the perirhinal cortex may also be involved. However, experimental parameters differ substantially across studies, which limits our ability to fully understand the fundamental contributions of these structures. In fact, previous studies vary in the type of temporal memory they emphasize (e.g., order, sequence, or separation in time), the stimuli and responses they use (e.g., trial-unique or repeated sequences, and incidental or rewarded behavior), and the degree to which they control for potential confounding factors (e.g., primary and recency effects, or order memory deficits secondary to item memory impairments). To help integrate these findings, we developed a new paradigm testing incidental memory for trial-unique series of events, and concurrently assessed order and item memory in animals with damage to the hippocampus, prefrontal cortex, or perirhinal cortex. We found that this new approach led to robust order and item memory, and that hippocampal, prefrontal and perirhinal damage selectively impaired order memory. These findings suggest the hippocampus, prefrontal cortex and perirhinal cortex are part of a broad network of structures essential for incidentally learning the order of events in episodic memory

A Gender Comparison of Economists' Publications

An ordered probit model is used to examine the impact of gender and the quality of the PhD g ranting in stitution o n the publication r ecord of m ale an d f emale economists who received t heir doctorate i n 1985. This analysis indicates th at men an d women have different publ ication pa tterns regardless of where t hey r eceived t heir P hD and t hat the quality of t he P hD granting institution has n o m easurable effect o n an individual's publication record.gender, ordered probit model, journal publications