A Retrospective Analysis of Nutritional Parameters in Chronic Obstructive Pulmonary Disease between Sexes

The aim of this study was to reveal the relationships between nutritional parameters and pulmonary functions in patients with chronic obstructive pulmonary disease (COPD) in both sexes. Spirometric, laboratory, and demographic data of 450 consecutive patients were analysed retrospectively. Males had significantly greater pack-years of smoking, more severe airway obstruction, and lower body mass index (BMI). In non-smokers, BMI was significantly lower in men independent of age and pulmonary functions. Creatine kinase levels showed no correlation with any pulmonary function parameters. Serum albumin levels correlated better than BMI with pulmonary functions. In conclusion, females with COPD were maintained weight better than men

Hippocampus and retrosplenial cortex combine path integration signals for successful navigation

The current study used fMRI in humans to examine goal-directed navigation in an open field environment. We designed a task that required participants to encode survey-level spatial information and subsequently navigate to a goal location in either first person, third person, or survey perspectives. Critically, no distinguishing landmarks or goal location markers were present in the environment, thereby requiring participants to rely on path integration mechanisms for successful navigation. We focused our analysis on mechanisms related to navigation and mechanisms tracking linear distance to the goal location. Successful navigation required translation of encoded survey-level map information for orientation and implementation of a planned route to the goal. Our results demonstrate that successful first and third person navigation trials recruited the anterior hippocampus more than trials when the goal location was not successfully reached. When examining only successful trials, the retrosplenial and posterior parietal cortices were recruited for goal-directed navigation in both first person and third person perspectives. Unique to first person perspective navigation, the hippocampus was recruited to path integrate self-motion cues with location computations toward the goal location. Last, our results demonstrate that the hippocampus supports goal-directed navigation by actively tracking proximity to the goal throughout navigation. When using path integration mechanisms in first person and third person perspective navigation, the posterior hippocampus was more strongly recruited as participants approach the goal. These findings provide critical insight into the neural mechanisms by which we are able to use map-level representations of our environment to reach our navigational goals

R&D and productivity in OECD firms and industries: A hierarchical meta-regression analysis

The relationship between R&D investment and firm/industry productivity has been investigated widely following seminal contributions by Zvi Griliches and others from late 1970s onwards. We aim to provide a systematic synthesis of the evidence, using 1253 estimates from 65 primary studies that adopt the so-called primal approach. In line with prior reviews, we report that the average elasticity and rate-of-return estimates are positive. In contrast to prior reviews, however, we report that: (i) the estimates are smaller and more heterogeneous than what has been reported before; (ii) residual heterogeneity remains high among firm-level estimates even after controlling for moderating factors; (iii) firm-level rates of return and within-industry social returns to R&D are small and do not differ significantly despite theoretical predictions of higher social returns; and (iv) the informational content of both elasticity and rate-of-return estimates needs to be interpreted cautiously. We conclude by highlighting the implications of these findings for future research and evidence-based policy

The Weevil Next Door: Exploring the impact of associational effects on C. pitcheri to better biological control practices

Lake Michigan dwelling dune thistle, Circium pitcheri, is a federally threatened plant, whose reproduction is affected by a non-native weevil, Larinus planus. Originally introduced as a biological control agent to combat the spread of Canada thistle, Circium arvense, this weevil is instead using C. pitcheri as a host for its larvae. Associational susceptibility is an important factor to consider in hopes of preventing the damage to this endangered plant. The goal of this study was to observe L. planus behavior to determine why there is a correlation between increased density of beach grass and high levels of C. pitcheri damage. We hypothesize that C. pitcheri’s neighboring grass community is used as a dispersal aid for the non-native weevil, making neighboring thistle hosts more susceptible to weevil damage in grassy environments. To test this, we conducted ethogram studies at Whitefish Dunes State Park (WDSP) in Door County, WI. At WDSP, we found that L. planus physically used beach grass to get to C. pitcheri and largely failed to disperse using the sand. These results should help provide ecologically sustainable management strategies, while also promote more in-depth host specific analyses prior to the release of biological control agents

Chaos edges of zz-logistic maps: Connection between the relaxation and sensitivity entropic indices

Chaos thresholds of the $z$-logistic maps $x_{t+1}=1-a|x_t|^z$ $(z>1; t=0,1,2,...)$ are numerically analysed at accumulation points of cycles 2, 3 and 5. We verify that the nonextensive $q$-generalization of a Pesin-like identity is preserved through averaging over the entire phase space. More precisely, we computationally verify $\lim_{t \to\infty}< S_{q_{sen}^{av}} >(t)/t= \lim_{t \to\infty}(t)/t \equiv \lambda_{q_{sen}^{av}}^{av}$, where the entropy $S_{q} \equiv (1- \sum_i p_i^q)/ (q-1)$ ($S_1=-\sum_ip_i \ln p_i$), the sensitivity to the initial conditions $\xi \equiv \lim_{\Delta x(0) \to 0} \Delta x(t)/\Delta x(0)$, and $\ln_q x \equiv (x^{1-q}-1)/ (1-q)$ ($\ln_1 x=\ln x$). The entropic index $q_{sen}^{av}0$ depend on both $z$ and the cycle. We also study the relaxation that occurs if we start with an ensemble of initial conditions homogeneously occupying the entire phase space. The associated Lebesgue measure asymptotically decreases as $1/t^{1/(q_{rel}-1)}$ ($q_{rel}>1$). These results led to (i) the first illustration of the connection (conjectured by one of us) between sensitivity and relaxation entropic indices, namely $q_{rel}-1 \simeq A (1-q_{sen}^{av})^\alpha$, where the positive numbers $(A,\alpha)$ depend on the cycle; (ii) an unexpected and new scaling, namely $q_{sen}^{av}(cycle n)=2.5 q_{sen}^{av}(cycle 2)+ \epsilon$ ($\epsilon=-0.03$ for $n=3$, and $\epsilon = 0.03$ for $n=5$).Comment: 5 pages, 5 figure

A push-pull transducer for ocean wave energy harvesting

Ocean wave energy is one of the primary energy sources, which is available during day and night, in various weather conditions. It was previously proven that energy harvesting from ocean waves could be used to generate electric power to supply sensors or small electronic devices located in buoys. Using a combination of various energy harvesters would enable more remote and unmanned future offshore sensor applications that can facilitate more effective monitoring and control. In this study, we successfully demonstrated a simple, low-cost and environmentally friendly energy harvester which can be optimally used as an Ocean Wave Energy Harvester (OWEH). Please click Additional Files below to see the full abstract

Probability densities for the sums of iterates of the sine-circle map in the vicinity of the quasi-periodic edge of chaos

We investigate the probability density of rescaled sum of iterates of sine-circle map within quasi-periodic route to chaos. When the dynamical system is strongly mixing (i.e., ergodic), standard Central Limit Theorem (CLT) is expected to be valid, but at the edge of chaos where iterates have strong correlations, the standard CLT is not necessarily to be valid anymore. We discuss here the main characteristics of the central limit behavior of deterministic dynamical systems which exhibit quasi-periodic route to chaos. At the golden-mean onset of chaos for the sine-circle map, we numerically verify that the probability density appears to converge to a q-Gaussian with q<1 as the golden mean value is approached.Comment: 7 pages, 7 figures, 1 tabl

Analysis of return distributions in the coherent noise model

The return distributions of the coherent noise model are studied for the system size independent case. It is shown that, in this case, these distributions are in the shape of q-Gaussians, which are the standard distributions obtained in nonextensive statistical mechanics. Moreover, an exact relation connecting the exponent $\tau$ of avalanche size distribution and the q value of appropriate q-Gaussian has been obtained as q=(tau+2)/tau. Making use of this relation one can easily determine the q parameter values of the appropriate q-Gaussians a priori from one of the well-known exponents of the system. Since the coherent noise model has the advantage of producing different tau values by varying a model parameter \sigma, clear numerical evidences on the validity of the proposed relation have been achieved for different cases. Finally, the effect of the system size has also been analysed and an analytical expression has been proposed, which is corroborated by the numerical results.Comment: 14 pages, 3 fig