The effects of temperature on population dynamics of Daphnia magna : a modelling study

In this study, the effects of temperature on population dynamics of Daphnia magna are examined using a mathematical model based on the dynamics of individual daphnid. Relationships between temperature and physiological parameters of the organisms are modelled using two exponential forms. Upper and lower survival threshold temperatures are found by means of multiple computer simulations at various constant temperatures. Optimal biomass production is examined and the optimal temperature that maximizes population biomass is also found. The effect of seasonality on the total biomass of the population is also studied by considering temperature as a function of time

Financing framework for local governments: diagnosis and change proposals

Motivation: The best way to widen access to public services at the local level is to increase efficiency of local government spending. However, an increase in efficiency may refer to output or inputs. In the latter case it does not widen access to public services. Moreover, factors conducive to spending efficiency may be detrimental to local cohesion. Finding a way so that the financing framework for local governments would reconcile the efficiency condition with the conditions of access to public services and local cohesion respectively, is an issue of great importance for economic policy. It seems to be so especially in a country like Poland, where there are large differences in the level of development between regions for historical reasons. These differences, if left accumulating, could easily jeopardize efficiency due to distorted capital flows, not to mention political tensions they may cause. Aim: The article aims at identifying basic features of the financing framework for local governments in Poland that hinder efficiency of their spending and at proposing feasible changes to that framework that would improve the efficiency but not at the expense of local cohesion or access to public services. Results: The article argues that the financing framework of local governments in Poland would better meet conditions of both efficiency and access to public services, if local governments relied mostly on revenues from income taxes instead of transfers from the central government, and some elements of tax competition between local authorities, although restricted to PIT-free allowance, were introduced. Such a shift in local governments revenue composition would not weaken local cohesion, if it was accompanied by an appropriate solidarity subvention financed by the richest voivodeship and the central government, and non-recurring central government revenues were allocated to investments exceeding financial capacity of local governments

Deep Machine Learning with Spatio-Temporal Inference

Deep Machine Learning (DML) refers to methods which utilize hierarchies of more than one or two layers of computational elements to achieve learning. DML may draw upon biomemetic models, or may be simply biologically-inspired. Regardless, these architectures seek to employ hierarchical processing as means of mimicking the ability of the human brain to process a myriad of sensory data and make meaningful decisions based on this data. In this dissertation we present a novel DML architecture which is biologically-inspired in that (1) all processing is performed hierarchically; (2) all processing units are identical; and (3) processing captures both spatial and temporal dependencies in the observations to organize and extract features suitable for supervised learning. We call this architecture Deep Spatio-Temporal Inference Network (DeSTIN). In this framework, patterns observed in pixel data at the lowest layer of the hierarchy are organized and fit to generalizations using decomposition algorithms. Subsequent spatial layers draw upon previous layers, their own temporal observations and beliefs, and the observations and beliefs of parent nodes to extract features suitable for supervised learning using standard classifiers such as feedforward neural networks. Hence, DeSTIN is viewed as an unsupervised feature extraction scheme in the sense that rather than relying on human engineering to determine features for a particular problem, DeSTIN naturally constructs features of interest by representing salient regularities in the patterns observed. Detailed discussion and analysis of the DeSTIN framework is provided, including focus on its key components of generalization through online clustering and temporal inference. We present a variety of implementation details, including static and dynamic learning formulations, and function approximation methods. Results on standardized datasets of handwritten digits as well as face and optic nerve detection are presented, illustrating the efficacy of the proposed approach

Binding of cytohesin 2 to the plasma membrane and its relationship with the EGFR

Eukaryotic cells are compartmentalized by lipid membranes to achieve the spatial separation of biological processes and signaling pathways. Controlled trafficking of proteins between these compartments as well as the recruitment of proteins to the membranes themselves are crucial for trouble-free function of the cell. Previous research has revealed several possibilities for interaction between proteins and membranes. Phosphoinositides can specifically interact with certain protein domains, anionic lipids attract positively charged protein domains by electrostatic force and lipids can even be attached to proteins post-translationally to enable integration into the membrane. This work focuses on the guanine nucleotide exchange factor ARNO, a multidomain protein that activates small GTPases like Arf6 and therefore is directly involved in the vesicle trafficking machinery of the cell. In its autoinhibited form, ARNO is localized in the cytoplasm, whereas recruitment to the plasma membrane is a prerequisite for its activation of Arf. So far, research has been centered on the interaction of the PH-domain and the PBR-domain of ARNO with artificial membrane systems. To expand these findings and account for the enormous complexity of the inner leaflet of the cellular plasma membrane, in this study, membrane sheets are employed. The ability of a variety of protein constructs consisting of different ARNO domains to bind to these sheets is analyzed. It seems that the different domains of ARNO aid to the interaction with the membrane in a cooperative manner. While the PH-domain is absolutely required for association with the membrane, it is not sufficient for sequestration of ARNO in the membrane. Moreover, its interaction with the phosphoinositides could be altered by the concentration of calcium in the binding buffer. Hypothetically, this might be due to the formation of PIP-bridges permitted by the crosslinking of individual PIP molecules by the Ca2+ ions. This results in a loss of accessibility of the PIPs for binding by the ARNO PH-domain. In this work, binding studies of the other ARNO domains conclusively show that the PBR-domain, the Sec7-domain as well as the coiled-coil domain participate in plasma membrane binding. Moreover, dimerization of ARNO also improves its binding ability, most probably by an increase of the local avidity. Once bound to the plasma membrane, ARNO proteins form clusters. Brightfield as well as STED microscopy reveals that these overlap with clusters of the endogenous EGFR to a non-random degree. Having observed this colocalization, a possible biological relationship between ARNO and the EGFR is assessed. Overexpression of ARNO in HeLa cells results in a tendency towards increased activation of the EGFR after stimulation with EGF. Upon activation, the EGFR can be translocated to the nucleus by retrograde endosomal trafficking. Its JM-domain of the EGFR has been proposed as a possible binding partner for ARNO in previous studies and contains the nuclear localization signal of the EGFR. This work explores in how far overexpression or inhibition of ARNO influences the nuclear translocation of the EGFR. However, this does not seem to be the case

The impact of rehabilitation on the functioning of patients with amyotrophic lateral sclerosis: a pilot study

Background. Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurologic disorder during which results in a progressive deterioration of motor function. Rehabilitation is one of the elements of symptomatic treatment in patients with ALS. The aim of the study was to evaluate the impact of rehabilitation on the functioning of ALS patients in terms of daily living activities. Material and methods. Ten ALS patients participated in this pilot study. The study involved completing a questionnaire by the patient. The questionnaire consisted of 5 parts: general information of the patient, the Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS), the Edmonton Symptom Assessment Scale (ESAS), the Hospital Anxiety and Depression Scale — Modified Version (HADS-M) and the part assessing the impact of rehabilitation on the patient’s functioning. Results. Most patients reported that rehabilitation was helping them breathe, reduced pain and improved sleep quality. An improvement in mental state was also observed in most patients. According to the responses provided by the patients, the treatment often led to hardly any or no improvement at all in terms of such activities as: walking, walking up and down the stairs, writing or preparing meals. Conclusions. Rehabilitation should be an element of symptomatic treatment provided to patients with ALS, at least because it has been shown to improve their mental state, although in many cases therapy has very little effect overall. The information provided in this paper may be of value for carers and physiotherapists working with the patients, as it may enable them to increase the effectiveness of their decisions to improve the patients’ comfort and quality of life.Background. Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurologic disorder during which results in a progressive deterioration of motor function. Rehabilitation is one of the elements of symptomatic treatment in patients with ALS. The aim of the study was to evaluate the impact of rehabilitation on the functioning of ALS patients in terms of daily living activities. Material and methods. Ten ALS patients participated in this pilot study. The study involved completing a questionnaire by the patient. The questionnaire consisted of 5 parts: general information of the patient, the Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS), the Edmonton Symptom Assessment Scale (ESAS), the Hospital Anxiety and Depression Scale — Modified Version (HADS-M) and the part assessing the impact of rehabilitation on the patient’s functioning.Results. Most patients reported that rehabilitation was helping them breathe, reduced pain and improved sleep quality. An improvement in mental state was also observed in most patients. According to the responses provided by the patients, the treatment often led to hardly any or no improvement at all in terms of such activities as: walking, walking up and down the stairs, writing or preparing meals. Conclusions. Rehabilitation should be an element of symptomatic treatment provided to patients with ALS, at least because it has been shown to improve their mental state, although in many cases therapy has very little effect overall. The information provided in this paper may be of value for carers and physiotherapists working with the patients, as it may enable them to increase the effectiveness of their decisions to improve the patients’ comfort and quality of life

Identity masking effectiveness and gesture recognition: Effects of eye enhancement in seeing through the mask

Face identity masking algorithms developed in recent years aim to protect the privacy of people in video recordings. These algorithms are designed to interfere with identification, while preserving information about facial actions. An important challenge is to preserve subtle actions in the eye region, while obscuring the salient identity cues from the eyes. We evaluated the effectiveness of identity-masking algorithms based on Canny filters, applied with and without eye enhancement, for interfering with identification and preserving facial actions. In Experiments 1 and 2, we tested human participants' ability to match the facial identity of a driver in a low resolution video to a high resolution facial image. Results showed that both masking methods impaired identification, and that eye enhancement did not alter the effectiveness of the Canny filter mask. In Experiment 3, we tested action preservation and found that neither method interfered significantly with driver action perception. We conclude that relatively simple, filter-based masking algorithms, which are suitable for application to low quality video, can be used in privacy protection without compromising action perception.Comment: 8 pages, 8 figure

News Sharing in Social Media: A Review of Current Research on News Sharing Users, Content, and Networks

This article provides a review of scientific, peer-reviewed articles that examine the relationship between news sharing and social media in the period from 2004 to 2014. A total of 461 articles were obtained following a literature search in two databases (Communication & Mass Media Complete [CMMC] and ACM), out of which 109 were deemed relevant based on the study’s inclusion criteria. In order to identify general tendencies and to uncover nuanced findings, news sharing research was analyzed both quantitatively and qualitatively. Three central areas of research—news sharing users, content, and networks—were identified and systematically reviewed. In the central concluding section, the results of the review are used to provide a critical diagnosis of current research and suggestions on how to move forward in news sharing research

Effect of Ti Nspire on Resource Algebra Students’ Mathematics Achievement and Attitude

The use of the calculator in a mathematics class has been studied and debated since the calculator was first introduced into the classroom. As the technology of calculators have evolved into interactive learning tools, little research could be found about the effects of an interactive calculator on the mathematical achievement and attitudes of students with disabilities. To determine if the TI Nspire handheld calculator is effective in increasing mathematical achievement and attitudes of students with disabilities, a qualitative-dominant mixed method approach was used. Interviews with an Algebra I teacher of students with disabilities were held to determine the teacher’s perception of teaching with the TI Nspire. Interviews with students in Resource Algebra I classes were held to ascertain the mathematical attitudes of the students while pre- and post-test scores from students at the beginning and end of the course were analyzed quantifiably. Pre- and post-tests from the control group were administered during the second half of their Algebra I course. The intervention group were administered the pre- and post-tests during the first half of their Algebra I course with an additional pre-test given at the beginning of the second half of their Algebra I course. Analysis resulted in no statistically significant differences; however, with effect sizes of Cohen’s d between 0.121 and 0.541, a level of practical significance was found. Interviews with six students from the control group and eight students from the intervention group were held to ascertain student attitudes towards mathematics. Statements from the interviews were coded as positive, negative, and neutral. Results determined the overall statements provided by the intervention group contained 6% more positive than negative statements. Statements provided by the control group were more negative than positive by 2%. A pre-intervention and post-intervention interview was conducted with the teacher of the Algebra I classes. Statements provided by the teacher were coded as positive, negative, neutral, and example. The teacher’s attitude toward the use of the TI Nspire as a teaching tool became more positive as evidenced by the increase in positive statements from the pre-intervention to post-intervention interview