Miracle-dz/UniFAR-FTUs huggingface dataset:
Rsp Inhibits Attachment and Biofilm Formation by Repressing fnbA in Staphylococcus aureus MW2

ABSTRACT Biofilms contribute to virulence of Staphylococcus aureus. Formation of biofilms is multifactorial, involving polysaccharide, protein, and DNA components, which are controlled by various regulators. Here we report that deletion of the rsp gene resulted in an increase in biofilm formation in strain MW2, suggesting that Rsp is a repressor of biofilm formation. Using SDS-PAGE, we found that Rsp profoundly affected cell surface and secreted proteins. The rsp gene was transcribed monocistronically, and the transcripts were most abundant at the exponential growth phase. Microarray analyses revealed that Rsp represses 75 genes, including 9 genes encoding cell wall-anchored proteins, and activates 22 genes, including 5 genes encoding secreted proteases. Among these genes, fnbA, fnbB, sasG, and spa (which encode cell wall-anchored proteins) and splABCD (which encode secreted proteases) have been implicated in biofilm formation. To deconvolute Rsp's contribution to biofilm formation, we analyzed deletion mutants of these genes either in the wild-type or in the rsp mutant background. We found that fnbA deletion in the rsp mutant restored biofilm formation to the wild-type level, indicating that FnbA plays a major role in Rsp regulation of biofilm formation. Further studies revealed that Rsp inhibited biofilm formation at the stage of primary attachment through repressing fnbA. Rsp belongs to the AraC/XylS family of regulatory proteins. We expressed the putative Rsp DNA binding domain (RspDBD) in Escherichia coli and showed that RspDBD was able to specifically bind to a short DNA fragment containing the fnbA promoter, suggesting that Rsp represses fnbA expression by direct DNA binding.
Inner Meniscus Cells Maintain Higher Chondrogenic Phenotype Compared with Outer Meniscus Cells

Meniscus cells have several distinct properties in cellular morphology and extracellular matrix production. Inner meniscus cells are considered to have more chondrocytic phenotype compared with outer meniscus cells. However, the chondrogenic property of each meniscus cell has not been elucidated in detail. In this study, we investigated the difference between human inner and outer meniscus-derived cells in extracellular matrix deposition and chondrogenic potential. Monolayer-cultured inner meniscus cells showed small and ovoid shapes though slender and fibroblastic cells were obtained from outer half of human meniscus. The syntheses of type II collagen and safranin O-stained proteoglycans were increased in chondrogenic pellets derived from inner meniscus cells, rather than in outer meniscus cell-derived pellets. On the other hand, adipogenic lipid vacuoles were equally accumulated in both inner and outer meniscus cells after adipogenic treatment. Chondrogenic treatments also enhanced the expression of chondrogenic marker genes, such as Sry-type HMG box (SOX) 9, Scleraxis, and α1(II) collagen, in inner meniscus cells. However, SOX9 expression was not increased in outer meniscus cells even after chondrogenic treatment. This study demonstrated that inner meniscus cells maintained higher chondrogenic potential compared with outer meniscus cells. Our results suggest that the difference between inner and outer meniscus cells in chondrogenic property might have an essential role in preserving a zone-specific meniscal feature.
Bilateral Facilitation and Laterality during the Countermovement Jump

This study assessed bilateral facilitation and laterality during counter-movement jumps. 23 NCAA Division-I athletes (13 men, 10 women) who participated in track and field volunteered to serve as participants and performed bilateral, right, and left leg countermovement jumps on a force plate. Dependent variables included jump height, reactive strength index, and time to stabilization. A one-way analysis of variance showed significant sex differences in single-leg and bilateral jump height and left leg and bilateral reactive strength index. No sex differences were found for time to stabilization. A repeated-measures analysis of variance indicated significant main effects for jump height and reactive strength index but not for time to stabilization. Bonferroni adjusted pairwise comparisons showed that bilateral jump height and reactive strength index values were different from the unilateral conditions. No differences were found between the right and left legs for jump height, reactive strength index, or time to stabilization. Results indicated no evidence of laterality as assessed by jump height, reactive strength index, and time to stabilization. Bilateral facilitation was found as assessed by jump height and reactive strength index. Time to stabilization demonstrated a bilateral deficit phenomenon.
Developing E-Loyalty Amongst Impulsive Buyers via Social Influence on Group Buying Websites

Group buying websites typically need a pre-determined minimum number of buyers for a deal before that deal is on. With the proliferation of these websites, it becomes very crucial for marketers to understand how they can capture online group sales early. Consumers at group buying websites are usually not aware of the deals prior visiting the websites. Therefore purchases made at group buying websites are usually impulse purchases, i.e. unplanned buys. With a 24-hour countdown timer or an indication of the number of deals sold in real time, consumers may be misled into committing to purchases, which may cause them to have negative feelings and hence low loyalty. This study therefore serves to investigate loyalty in group buying websites. In trying to “tempt” consumers to buy the deals impulsively, it is important to understand how this will eventually affect their loyalty. Knowing what can motivate consumers to make a purchase as early as possible is also important. Our findings help group buying websites understand how they can better design their online platforms so that they can get consumers to commit fast, while still build loyalty in them. This is very important in ensuring the long-term survival of group buying websites.
Probiotics, Prebiotics and Immunomodulation of Gut Mucosal Defences: Homeostasis and Immunopathology

Probiotics are beneficial microbes that confer a realistic health benefit on the host, which in combination with prebiotics, (indigestible dietary fibre/carbohydrate), also confer a health benefit on the host via products resulting from anaerobic fermentation. There is a growing body of evidence documenting the immune-modulatory ability of probiotic bacteria, it is therefore reasonable to suggest that this is potentiated via a combination of prebiotics and probiotics as a symbiotic mix. The need for probiotic formulations has been appreciated for the health benefits in “topping up your good bacteria” or indeed in an attempt to normalise the dysbiotic microbiota associated with immunopathology. This review will focus on the immunomodulatory role of probiotics and prebiotics on the cells, molecules and immune responses in the gut mucosae, from epithelial barrier to priming of adaptive responses by antigen presenting cells: immune fate decision—tolerance or activation? Modulation of normal homeostatic mechanisms, coupled with findings from probiotic and prebiotic delivery in pathological studies, will highlight the role for these xenobiotics in dysbiosis associated with immunopathology in the context of inflammatory bowel disease, colorectal cancer and hypersensitivity.
Analysis and Optimization of Cellular Network with Burst Traffic

In this paper, we analyze the performance of cellular networks and study the optimal base station (BS) density to reduce the network power consumption. In contrast to previous works with similar purpose, we consider Poisson traffic for users' traffic model. In such situation, each BS can be viewed as M/G/1 queuing model. Based on theory of stochastic geometry, we analyze users' signal-to-interference-plus-noise-ratio (SINR) and obtain the average transmission time of each packet. While most of the previous works on SINR analysis in academia considered full buffer traffic, our analysis provides a basic framework to estimate the performance of cellular networks with burst traffic. We find that the users' SINR depends on the average transmission probability of BSs, which is defined by a nonlinear equation. As it is difficult to obtain the closed-form solution, we solve this nonlinear equation by bisection method. Besides, we formulate the optimization problem to minimize the area power consumption. An iteration algorithm is proposed to derive the local optimal BS density, and the numerical result shows that the proposed algorithm can converge to the global optimal BS density. At the end, the impact of BS density on users' SINR and average packet delay will be discussed.
SybilLimit: A Near-Optimal Social Network Defense Against Sybil Attacks

Open-access distributed systems such as peer-to-peer systems are particularly vulnerable to sybil attacks, where a malicious user creates multiple fake identities (called sybil nodes). Without a trusted central authority that can tie identities to real human beings, defending against sybil attacks is quite challenging. Among the small number of decentralized approaches, our recent SybilGuard protocol leverages a key insight on social networks to bound the number of sybil nodes accepted. Despite its promising direction, SybilGuard can allow a large number of sybil nodes to be accepted. Furthermore, SybilGuard assumes that social networks are fast-mixing, which has never been confirmed in the real world. This paper presents the novel SybilLimit protocol that leverages the same insight as SybilGuard, but offers dramatically improved and near-optimal guarantees. The number of sybil nodes accepted is reduced by a factor of Θ(√n), or around 200 times in our experiments for a million-node system. We further prove that SybilLimit's guarantee is at most a logn factor away from optimal when considering approaches based on fast-mixing social networks. Finally, based on three large-scale real-world social networks, we provide the first evidence that real-world social networks are indeed fast-mixing. This validates the fundamental assumption behind SybilLimit's and SybilGuard's approach.
Biomechanical effects of plate area and locking screw on medial open tibial osteotomy

Medial open high tibial osteotomy (HTO) has been used to treat osteoarthritis of the medial compartment of the knee. However, weaker plate strength, unstable plate/screw junction and improper surgery technique are highly related to the HTO outcomes. Two π-shape plates were designed and eight variations (two supporting area × four locking stiffness) were compared by finite-element method. The computed tomography-based tibia was reconstructed and both wedge micromotion and implant stresses were chosen as the comparison indices. The construct was subjected to surgical and physiological loads. The medial-posterior region is the most loaded region and the load through the posterior leg is about four times that through the anterior leg. This indicates that the two-leg design can form a force-couple mechanism to effectively reduce the implant stresses. The use of locking screws significantly decrease the screw and hole stresses. However, the extending plate reduces the stresses of screws and holes above the wedge but makes the distal screws and holes much stressed. Wedge micromotion is affected by extending plate rather than locking screw. Three factors contribute to effective stabilisation of unstable HTO wedge: (1) intimate tibia–plate contact at medial-posterior regions, (2) sufficient rigidity at plate-screw junctions and (3) effective moment-balancing design at distal tibia–plate interfaces.
CD66b Overexpression and Loss of C5a Receptors as Surface Markers for Staphylococcus aureus-Induced Neutrophil Dysfunction

Neutrophil granulocytes constitute the main component of innate immunity in the clearance of bacterial infections. However, during systemic inflammation, immunoparalysis may occur resulting in neutrophil dysfunction. This study presents a new in vitro model for analyzing the dysfunction of human peripheral blood neutrophils resulting from the interaction with Staphylococcus aureus components in whole blood. After induction of a massive complement activation by S. aureus supernatant, the neutrophils exhibit a reduced phagocytic capacity resulting in a dramatic reduction of the antibacterial activity similar to that of neutrophils isolated from septic patients. The number of phagocytozing neutrophils is drastically reduced as well as the phagocytic capacity designated by a significantly lower number of ingested microbes. This dysfunction correlates with the loss of complement component 5a receptor 1 from the neutrophil cell surface and can be further characterized by a C5a-induced CD66b overexpression. The presented in vitro model offers a new platform for preclinical testing of immunosuppressive drugs and delivers new information for the understanding of neutrophil dysfunctions under the conditions described.
On Space–Frequency Correlation of UWB MIMO Channels

Conventional multiple-input-multiple-output (MIMO) channel correlation models focus on describing the complex amplitude correlation of resolvable multipath components (MPCs). It has recently been shown that the time-of-arrival (ToA) correlation of resolvable MPCs, which has largely been ignored in the literature so far, is important for characterizing the space-frequency (SF) correlation of MIMO channels in the ultrawideband (UWB) regime. The proposal of ToA correlation brings forth the following open questions: What is the fundamental difference between amplitude and ToA correlations? Are they mutually replaceable? What impact do they have on system performance? Is this impact related to channel bandwidth? This paper systematically answers the above questions. We demonstrate that, compared with a conventional model that only considers amplitude correlation, a UWB MIMO channel model taking into account both amplitude and ToA correlations leads to different theoretical maximum diversity order, numerical structure of the SF channel covariance matrix, spatial correlation function, and diversity performance. We conclude that ToA correlation is a necessary complement to amplitude correlation when the channel bandwidth exceeds 500 MHz, i.e., UWB channels. This new insight serves as the motivation for more realistic modeling of UWB MIMO channels and the inspiration for designing advanced UWB MIMO systems to fully exploit the SF channel correlation properties.
Effect of Gum Arabic on Liver Function And Antioxidant Enzymes of Sprague-Dawley Rats

The aim of this study was to investigate the effect of twelve weeks Gum Arabic dose on the liver functions and some antioxidant enzymes activity of 10 Sprague-Dawley rats. Methods: 10 normal Sprague-Dawley rats were fed one liter 10% of gum Arabic solution daily for 12 weeks. As a control group another 10 rats were not fed with gum Arabic. On week twelve, blood samples were collected from each rat and all of them were killed and the liver was obtained. Some of the liver was homogenized and the supernatant was collected. The liver function tests (direct bilirubin, total bilirubin, albumin, total proteins, Asparate transaminase, alanine transaminase and alkaline phosphatase) were done using the blood samples and the supernatant of the homogenized liver was used to detect the activity of superoxide dismutase and catalase and to measure the concentration of glutathione and Malondialdehyde (MDA). Results: the comparison of the mean values of the liver function tests showed the absence of significant variation between the liver function tests in the control and the gum Arabic fed rats. Concerning the antioxidant parameters, there was significant increase in the superoxide dismutase (p-value≤ 0.000), catalase (p-value= 0.043), glutathione (p-value= 0.004) and significant decrease in the MDA concentration (p-value≤ 0.000). Conclusion: Daily gum Arabic dose for twelve weeks significantly affected the liver antioxidant activity of Sprague-Dawley rats.
Perceived Social Support from Strength and Conditioning Coaches Among Injured Student Athletes

Abstract Judge, LW, Bellar, D, Blom, LC, Lee, D, Harris, B, Turk, M, McAtee, G, and Johnson, J. Perceived social support from strength and conditioning coaches among injured student-athletes. J Strength Cond Res 26(4): 1154–1161, 2012—Injuries suffered by student athletes not only affect their physical ability to perform in sport but also have psychological effects as well. The purpose of this study was to examine student athletes' perceptions, expectations, and satisfaction of the social support provided by their strength and conditioning coach (SC) during the later reconditioning stage of their rehabilitation and their views on the overall level of importance of each type of social support. One hundred and sixty-five participants aged 20.21 ± 1.32 years from 6 Division I Universities in the Midwest region of the USA completed the modified Social Support Survey. The results of a chi-square test assessing the responses for 6 types of social support provided by SCs based on athletes' age, gender, and sport revealed a significant difference (&khgr;2[13,105] = 26.46, p = 0.015) for listening support differing by sport. A significant difference (&khgr;2[13,105] = 267.74, p = 0.010) was also revealed for reported emotional challenge by sport. Results showed that the SC had a significant psychosocial impact on student-athletes' overall psychological well-being during reconditioning. This study provides evidence of the vital psychosocial role that SCs can play during an injured student-athlete's reconditioning program.
The Effect of Digital Nudging Techniques on Customers' Product Choice and Attitudes towards E-Commerce Sites

Digital nudging is receiving increasing attention by academics and practitioners in recent years. In this research, our main goal is to determine the relative impact of different nudging techniques on the customers’ product choice processes and their attitudes towards e-commerce sites employing these techniques. Specifically, we are interested in the interaction effects of defaulting, customer reviews (star ratings of products) and purchase pressure cues with the centrality choice bias. Prior research has predominantly investigated nudging techniques or positioning effects in separation. We try to fill this gap and explore possible interaction effects in an eye-tracking experiment. In our study, we plan to research not only the effects of digital nudging techniques on product choice, but also in how far they shape users’ attitudes towards an e-commerce site.
Patellar tracking measurement in the normal knee

Eleven fresh frozen cadaveric knee specimens were mounted in a knee kinematics test device, and normal patellar movements were evaluated with use of an external device for direct measurement of patellar movements. The effects of four different measurement conditions were assessed through alteration of one condition and determination of its effect on patellar kinematics with the use of six specimens. The four conditions included (a) change of the measuring axis from an axis parallel to the central axis of the femur (femoral axis) to one parallel to the central axis of the tibia (tibial axis), (b) rotation of the femoral axis internally 6°, (c) change of the direction of the quadriceps force from parallel to the mechanical line of the lower extremity to a direction parallel to the femoral shaft, and (d) increase of the magnitude of the quadriceps force from 111 to 500 N. During knee flexion, the patella shifted laterally after a slight initial medial shift, tilted laterally from midflexion to 90°, and gradually rotated medially. The patellar shift relative to the tibial axis appeared to be more medial than the shift measured relative to the femoral axis; the discrepancy was caused by the valgus position of the tibia relative to the femur. Changing the rotational angle of the femoral axis artifically changed the patellar position. Varying the direction of the quadriceps within the narrow range and increasing the quadriceps force did not affect patellar movements. It is likely that the anatomic configuration of the patella allows the patella to seat in a stable configuration so that it resists moderate changes in the load and direction of the quadriceps. Tibial rotation exerted a major influence on patellar shift and tilt in the early phase of knee flexion: the patella rotated medially when the tibia was externally rotated and rotated laterally when the tibia was internally rotated. These results indicate that the patella may be unstable in the first phase of knee flexion when the tibia is rotated.
Awareness and Practice of Biosecurity Measures in Small Scale Poultry Production in Ekiti State, Nigeria

The high susceptibility of poultry to disease outbreaks makes a comprehensive biosecurity technology a necessary practice in poultry farms to protect the farms from both intentional and unintentional threats from biological agents. Therefore this study evaluated the awareness and practice of biosecurity measures in small scale poultry production in Ekiti State, Nigeria. A total of 80 respondents were randomly selected for the study. Data were obtained with the aid of a pre tested structured questionnaire. The result shows that the most practiced biosecurity measures in the study area are the ones relating to regular clearing of the poultry environment, regular washing of the feeding and drinking troughs while the least observed one is the quarantine of the new birds. Also the result of the regression analysis shows that the level of education, farm size, formal training in poultry production and number of extension visits all have significant positive influence on the sampled farms' biosecurity control score while age, number of household labour, and distance from the nearest poultry farm shows significant negative influence on the farms' biosecurity control score. Equally, the result of the likert rating scale shows that the poultry farmers have a good knowledge of biosecurity measures with overall biosecurity knowledge index of 3.22. The study therefore recommends among other things the intensive sensitization of the poultry farmers through workshop and field days seminars by appropriate agents on the
Covariance estimation for distributions with 2+ε moments

We study the minimal sample size N=N(n) that suffices to estimate the covariance matrix of an n-dimensional distribution by the sample covariance matrix in the operator norm, with an arbitrary fixed accuracy. We establish the optimal bound N=O(n) for every distribution whose k-dimensional marginals have uniformly bounded 2+e moments outside the sphere of radius O(k√). In the specific case of log-concave distributions, this result provides an alternative approach to the Kannan–Lovasz–Simonovits problem, which was recently solved by Adamczak et al. [J. Amer. Math. Soc. 23 (2010) 535–561]. Moreover, a lower estimate on the covariance matrix holds under a weaker assumption—uniformly bounded 2+e moments of one-dimensional marginals. Our argument consists of randomizing the spectral sparsifier, a deterministic tool developed recently by Batson, Spielman and Srivastava [SIAM J. Comput. 41 (2012) 1704–1721]. The new randomized method allows one to control the spectral edges of the sample covariance matrix via the Stieltjes transform evaluated at carefully chosen random points.