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OBJECTIVE: Amyotrophic lateral sclerosis (ALS) is a multi-system disorder characterized primarily by motor neuron degeneration, but may be accompanied by cognitive dysfunction. Statistically appropriate criteria for establishing cognitive impairment (CI) in ALS are lacking. We evaluate quantile regression (QR), that accounts for age and education, relative to a traditional 2 standard deviation (SD) cut-off for defining CI. METHODS: QR of cross-sectional data from a multi-center North American Control (NAC) cohort of 269 healthy adults was used to model the 5(th) percentile of cognitive scores on the Edinburgh Cognitive and Behavioral ALS Screen (ECAS). The QR approach was compared to traditional 2 SD cut-off approach using the same NAC cohort (2SD-NAC) and to existing UK-based normative data derived using the 2SD approach (2SD-UK) to assess the impact of cohort selection and statistical model in identifying CI in 182 ALS patients. RESULTS: QR-NAC models revealed that age and education impact cognitive performance on the ECAS. Based on QR-NAC normative cutoffs, the frequency of CI in the 182 PENN ALS patients was 15.9% for ALS Specific, 12.6% for ALS Non-Specific and 15.4% for ECAS Total. This frequency of CI is substantially more conservative in comparison to the 2SD-UK (20.3%−34.6%) and modestly more conservative to the 2SD-NAC (14.3%−16.5%) approaches for estimating CI. CONCLUSIONS: The choice of normative cohort has a substantial impact and choice of statistical method a modest impact on defining CI in ALS. This report establishes normative ECAS thresholds to identify whether ALS patients in the North American population have CI.

ObjectivePlasma phosphorylated tau (p-tau181) is reliably elevated in Alzheimer’s disease (AD), but less explored is its specificity relative to other neurodegenerative conditions. Here we find novel evidence that plasma p-tau181 is elevated in amytrophic lateral sclerosis (ALS), a neurodegenerative condition typically lacking tau pathology. We performed a detailed clinical evaluation to unravel the potential source of this unexpected observation.MethodsPatients were clinically or pathologically diagnosed with ALS (n=130) or AD (n=82), or were healthy non-impaired controls (n=33). Receiver operating characteristic (ROC) curves were analyzed and area under the curve (AUC) was used to discriminate AD from ALS. Within ALS, Mann-Whitney-Wilcoxon tests compared analytes by presence/absence of upper motor neuron (UMN) and lower motor neuron (LMN) signs. Spearman correlations tested associations between plasma p-tau181 and postmortem neuron loss.ResultsA Wilcoxon test showed plasma p-tau181 was higher in ALS than controls (W=3297, p=0.0000020), and ROC analyses showed plasma p-tau181 poorly discriminated AD and ALS (AUC=0.60). In ALS, elevated plasma p-tau181 was associated with LMN signs in cervical (W=827, p=0.0072), thoracic (W=469, p=0.00025), and lumbosacral regions (W=851, p=0.0000029). In support of LMN findings, plasma p-tau181 was associated with neuron loss in the spinal cord (rho=0.46, p=0.017), but not in the motor cortex (p=0.41). CSF p-tau181 and plasma neurofilament light chain (NfL) were included as reference analytes, and demonstrate specificity of findings.InterpretationWe found strong evidence that plasma p-tau181 is elevated in ALS and may be a novel marker specific to LMN dysfunction.

Yoga is a codex of exercises for the body and mind originated in India. It has a series of benefits for health. However, it is challenging to find a standardized system of meditation and asanas, with a simple application so that it is readily applicable to a large population, as well as easy scientific reproducibility. Aiming to test a reproducible 8–week Yoga learning model, two healthy male subjects, one with 51 and the other with 54 years old, underwent eight sessions of meditation and carefully selected asanas for secure execution. Evaluations occurred before the first session and one day after the last session. The measured variables were blood pressure, heart rate, and global stretch. Both subjects presented improvements in the investigated variables. The proposed model is appropriate for the scientific study of Yoga.

ImportanceAmyotrophic lateral sclerosis (ALS) is a multi-system disorder characterized primarily by motor neuron degeneration, but may be accompanied by cognitive dysfunction. Statistically appropriate criteria for establishing cognitive impairment (CI) in ALS are lacking.ObjectiveDefine thresholds for CI in ALS using quantile regression (QR) that accounts for age and education in a North American (NAmer) cohort.DesignQR of cross-sectional data from a multi-center NAmer cohort of healthy adults was used to model the 5th percentile of cognitive scores on the Edinburgh Cognitive and Behavioral ALS Screen (ECAS). The QR approach was compared to a traditional 2 standard deviation (SD) cut-off approach using the same NAmer cohort (2SD-NAmer) and to existing UK-based normative data derived using the 2SD approach (2SD-UK) to assess the impact of cohort selection and statistical model in identifying CI ALS patients.Participants269 healthy adults from NAmer, recruited by the University of Pennsylvania (PENN; N=82), the University of Miami through the CRiALS study (CRiALS; N=40), and the Canadian ALS Neuroimaging Consortium (CALSNIC; N=147) were included to establish ECAS thresholds for defining CI. We then evaluated the frequency of CI in 182 ALS patients from PENN.Main OutcomesWe defined two new sets of normative thresholds, based on NAmer heathy adult performance, for each ECAS domain score and the composite scores using QR and 2SD statistical approaches. We then applied the 2SD-NAmer and QR-NAmer, as well as the previously established and widely-used 2SD-UK, thresholds to evaluate the frequency of CI in ALS patients.ResultsQR-NAmer models revealed that increased age and reduced educational attainment negatively impact cognitive performance on the ECAS. Based on the QR-NAmer normative cutoffs, the prevalence of CI in the 182 PENN ALS patients was 15.9% for ECAS ALS-Specific and 15.4% for ECAS Total. These estimates are more conservative than estimates ranging from 15.4%-34.6% impaired based on 2SD approaches.Conclusions and RelevanceThis report establishes normative thresholds for using ECAS to identify whether ALS patients in the NAmer population have CI. The choice of statistical method and normative cohort has a substantial impact on defining CI in ALS.Key PointsQuestionHow to define cognitive impairment (CI) in amyotrophic lateral sclerosis (ALS) using the Edinburgh Cognitive and Behavioral ALS Screen (ECAS)?FindingsAge- and education-adjusted quantile regression (QR) yields thresholds for defining CI that differ meaningfully from those derived from parametric methods without age- and education-adjustment. Thresholds also differ between UK and North American cohorts. Applying our North American-based QR norms to an American ALS cohort at a single center identified CI based on ECAS performance in ∼16% patients, compared to 15.4%-34.6% patients using other approaches.MeaningThe choice of statistical method and normative cohort has a substantial impact on defining CI in ALS.

El nuevo orden mundial, a través de la globalización y la perspectiva de los derechos humanos, ha reconfigurado el desarrollo de los conflictos; así, el protagonismo de los Estados se ha transformado gracias a la aparición de nuevos actores políticos y económicos que influyen en el escenario internacional. En esta coyuntura han aparecido las organizaciones de la sociedad civil, quienes han impulsado una agenda de participación ciudadana global, específicamente para la protección de los derechos humanos en los conflictos internacionales. Por esta razón, la sociedad civil requiere de instrumentos normativos e institucionales para la contención o solución del conflicto. Esta es la propuesta del presente ensayo, la elaboración de “Directrices para la participación de la sociedad civil en la mediación de los conflictos internacionales en materia de derechos humanos; ¨ con ello se pretende garantizar una mediación eficaz del conflicto y así, salvaguardar los derechos humanos de la población involucrada

Gastropod is one of the mollusk phylum that can adapt and decompose in mangrove forests. The mangrove forest in Sungai Kakap is an area that is slowly being opened due to the local community people’s activities. They opened land to build buildings, farms, and villages. This research is aimed at studying the diversity of Gastropod and the influence of the mangrove tree density on the gastropod diversity in the mangrove forest of Sungai Kakap, Sungai Kakap Village of Kubu Raya Regency. The data were taken in May 2018. The analysis was conducted using the observation method by making six observation lines. The lines were differentiated based on the density of the vegetations: dense, medium, and sparse. The number of Gastropods found in the Kakap River mangrove forest is 4 types of gastropods with a total of 252 individuals. Respectively from dense, medium, and sparse vegetation, the gastropod dominance index is 0.68, 0.37, and 0.51; the diversity index is 0.25, 0.49, and 0.33; the species average index is 0.27, 0.97, and 0.4; and the gastropod species richness index is 4.03, 1.18, and 0.7. Lastly, the species similarity index is respectively 86%, 66%, and 86%. Keywords: Gastropod, Mangrove Forests, Vegetation density.

Extreme infrastructure collapse poses unique challenges to emergency communications. This was the case in Puerto Rico in 2017 after hurricanes Irma and Maria. In this study, we first examined telecommunications carriers representatives' views of the adequateness of emergency communications policies. Their views were contrasted with the perspectives of a selection of telecommunications experts and regulators. Secondly, we conducted a policy analysis to assess the FCC, the Telecommunications Bureau of Puerto Rico, and telecommunications companies' emergency communications processes and outcomes. An electronic questionnaire and in-depth interviews with telecommunications companies' representatives, and secondary data analysis were used. The analysis revealed that most participants didn't consider favorably emergency communications polices at the federal level. Similarly, most considered state level policies as not adequate. The policy analysis points to ineffective federal and state emergency communications policies due to the impact of external factors and the lack of coordination of the state government electrical power provider and private telecommunications companies. The results also revealed that between 2017 and 2019 policymaking and the application of policy tools in regard to emergency communications were largely reactive and relying on a vigorous state level intervention in the telecommunications industry, as opposed to primarily regulating it. The analysis includes policy recommendations for emergency communications.

A 32-year-old man presented with a 10-day history of fever, chills, nausea, vomiting, myalgia, nonproductive cough, and worsening dyspnea after freshwater swimming in the Caribbean 1 week prior to presentation. Shortly after arrival at the hospital, the patient developed severe respiratory distress with massive hemoptysis. Based on serologic workup, he was diagnosed with leptospirosis pulmonary hemorrhage syndrome leading to diffuse alveolar hemorrhage, severe hypoxemic respiratory failure, and multiorgan failure. He received appropriate antibiotic coverage along with hemodynamic support with norepinephrine and vasopressin, mechanical ventilation, and renal replacement therapy in an intensive care unit. Introduction of extracorporeal membrane oxygenation was initiated to provide lung-protective ventilation supporting the recovery of his pulmonary function. Aminocaproic acid was used to stop and prevent further alveolar hemorrhage. He fully recovered thereafter; however, it is uncertain whether it was the use of aminocaproic acid that led to the resolution of his disease.

The paper analyzes refrigeration/HVAC system energy consumption in a typical food retail store to study the effects of indoor space conditions. Refrigerated display cases are normally rated at a store environment of 24 °C (75 °F) and a relative humidity of 55%. If the store can be maintained at lower relative humidity, significant quantities of refrigeration energy, defrost energy, and anti-sweat heater energy can be saved. Calculations were done for a typical day in a standard store for each month of the year using the climate data for Tampa, Florida. This results in a 24 h variation in the store relative humidity. Using these hourly values of relative humidity for a typical 24 h day, the store relative humidity distribution was calculated for a full year. The annual average supermarket relative humidity was found to be 51.1%. It is shown that for a 5% reduction in store relative humidity, the display case refrigeration load is reduced by 9.25%, and that results in total store energy load reduction of 4.84%. The results were compared to available experimental data and found to have a good agreement.

This study compares thermal environment of two air distribution systems in an office setting. Airflow, heat and mass (water vapor and contaminant gas) transfer in steady-state condition are modeled for an underfloor air distribution system and an overhead air distribution system. The models include a typical cubicle in a large office floor with a chair, a desk with a personal computer on top, and heat sources such as seated person, desktop computer, and lights. For underfloor air distribution system, cool air enters the occupied zone through an inlet located at the floor level supplying a vertical upward inflow. Three different locations of the inlet diffuser are considered. For overhead air distribution, the inlet is located on the ceiling with slower and cooler inflow. Three inlet angles are considered. For both systems, the air return location is on the ceiling at the same place. Distributions of velocity, temperature, relative humidity, and contaminant concentration in various cases for both systems are computed. Thermal comfort factors are assessed for the two systems. The results are compared among cases of each system, as well as between two typical cases of the two systems and to experimental data for an actual office building given in literature. The results provide a detailed understanding of air transport and its consequence on thermal comfort and indoor air quality that are useful for office building air conditioner design. It is found that underfloor system gives better performance than overhead system in contaminant removal and significantly in energy saving while maintaining the same thermal comfort condition.

A magnetic refrigerator consists of heat exchangers and beds of magnetic materials. The analysis considered a system that operates near room temperature in a magnetic field between 1 and 7.5 T and uses 3 kg of gadolinium (Gd) spheres, packed in two magnetocaloric beds. Different heat transfer fluids (water, ammonia, and R-134a) were used. The beds were periodically magnetized and demagnetized and the fluid flows were arranged to meet the cycle requirements. A sensitivity analysis was performed. Findings indicate that the higher the magnetic field, the higher the cooling power for the same temperature span. It was also observed that the cooling power decreases with increase in the temperature span for various magnetic fields. The ratio of COP actua l to the COP Carnot decreases with an increase in the temperature span. These trends as well as magnitudes of cooling power and coefficient performance were compared with experimental measurements and found to be in reasonably good agreement.

This paper presents air velocity and temperature distribution in a refrigerated warehouse. The refrigerated space under study has a set of ceiling-type cooling units installed in front of the arrays of stacks of palletized product packages. Numerical solutions of the steady-state airflow and heat transfer were done using a complete three-dimensional model and an equivalent two-dimensional model. The results obtained from both models were found to be in good agreement with each other. A parametric analysis was performed using the equivalent model with various values of blowing air velocity and locations of the cooling units. It was found that a better cooling effectiveness and uniformity of temperature in the refrigerated space could be achieved by using higher blowing air velocity and/or locating the cooling units lower and closer toward the arrays of product packages.

This paper presents a three-dimensional analysis for thermal comfort and contaminant removal in a hospital operating room. The room model includes a patient lying on an operating table, four surgical staff members standing around, and surgical lights above the patient. Cold clean air is supplied to the room through high sidewall grilles and exhausted through low sidewall grilles on the opposite wall. Steady-state heat and mass transfer in the room are simulated by employing computational fluid dynamics modeling approach. Solutions of the distribution of airflow velocity, temperature, relative humidity, and contaminant concentration are presented and discussed. The simulation results show a good agreement with experimental data from the literature. The predicted mean vote (PMV) is calculated for assessing thermal comfort of the occupants. The contaminant removal effectiveness (CRE) and the mean contaminant concentration in the breathing zone are used to assess the ventilation performance of the room. Effects of horizontal locations of supply and exhaust grilles on thermal comfort and contaminant removal are explored. Regression models for thermal comfort and contaminant removal as functions of these locations are built for design optimization. It is found that an overall better performance can be achieved by placing the supply grilles closer to the vertical centerline of the wall while the location of the exhaust grilles is somewhat insignificant.

A parametric analysis on the effect of using a ceiling fan in an air-conditioned room is performed by two-dimensional (2D) numerical simulation of steady state airflow and heat transfer. Thermal comfort analysis is done for a person standing in a room with an inlet and an outlet for air conditioning and a ceiling fan. Representative three-dimensional (3D) simulation is also performed for the comparison of results obtained by using 2D and 3D models. Distributions of velocity, temperature, and relative humidity are presented. Different cases in which the ceilings fan may be not in use or in use with different air speed normal to the plane of fan blades due to different rotational speeds are considered. Predicted mean vote is computed and used to assess the thermal comfort characteristics. It is found that as the normal air speed from the fan increases, thermal comfort significantly shifts toward the cooler scale to allow higher supply air temperature or higher heat load in the room while maintaining the same comfort level.

Heart failure (HF) is a multifactorial and progressive disease that has been linked to activation of the renin-angiotensin and sympathetic systems. In recent years, β-blockers have been shown to improve the status of HF patients, although the precise mechanisms remain unclear. The present study evaluates the effect of β-blockade with carvedilol (1 mg/kg/day) on cardiovascular function in 2- and 6-month-old cardiomyopathic hamsters (SCH) after 1-month and 5-month treatment periods with the drug, respectively. Age-matched golden hamsters were used as controls (CT). Systolic blood pressure (SBP) and echocardiographic studies were evaluated. The latter studies included left ventricular end-systolic (LVESV) and end-diastolic (LVEDV) volumes, ejection fraction (EF), cardiac output index (COI), heart rate (HR), and left ventricular posterior wall thickness (LVPWT). In 2-month-old SCH, carvedilol administration during a 1-month period reduced SBP from 107.59 ± 3.49 to 77.26 ± 3.49 mm Hg (n = 5, p < 0.05). At this stage, cardiac parameters in SCH were similar to those of controls and were not affected by carvedilol administration. In 6-month-old SCH, 5-month administration of carvedilol decreased SBP from 102.16 ± 3.61 to 90.60 ± 2.80 mm Hg (n = 5, p < 0.05), HR from 363 ± 14 to 324 ± 14 bpm (n = 5, p < 0.05), and LVESV from 0.18 ± 0.01 to 0.13 ± 0.01 ml/100 g BW (n = 5, p < 0.05), and increased EF and COI by 14 and 23%, respectively (n = 5, p < 0.05). The drug did not modify LVEDV or LVPWT. These results reveal that carvedilol significantly improves cardiac function in 6-month-old cardiomyopathic hamsters, but it does not prevent ventricular dilatation. Improved cardiac function appears to be secondary to decreased total peripheral resistance, due mainly to the vasodilator properties of the drug. Thus, overactivation of the sympathetic system is not likely to be a determining factor in the etiology of dilated cardiomyopathy in this animal model.

We report the case study of a 22-year-old woman with a>3-year history of dizziness. She described her dizziness episodes as “heavy headedness” and “feeling of imbalance” and was diagnosed with Chronic Subjective Dizziness (CSD). CSD has been shown to be linked to emotional disorders, particularly anxiety. During a seminar about the relationship between human standing posture and emotions, she performed a postural-emotional exercise along with the other seminar attendees. After the exercise the dizziness had completely resolved. One month later, in a scheduled interview, she reported being less anxious and had no further dizziness symptoms. Clinical trials should be conducted in order to better understand the effect of emotional treatments on CSD and Vestibular disorders in general.

OBJECTIVES To examine the presence of intestinal protozoan and helminth infections and their association with clinical signs and symptoms in children in Trujillo, Venezuela. METHODS Conventional microscopic methods (thick-smear, saline and iodine solutions) were used to identify parasites in stool samples of 301 children attending day care centres. A subgroup of 45 children was evaluated clinically and parasitologically five times during a 1-month period using conventional methods and the Kinyoun acid-fast stain for Cryptosporidium identification. RESULTS The point prevalence of protozoan infections was 21% for Giardia duodenalis, 1.0% for Entamoeba histolytica/dispar, 4% for Entamoeba coli, 16% for Blastocystis hominis, and 89% for Cryptosporidium parvum. Prevalence of helminth infection was 11% for Ascaris lumbricoides, 10% for Trichuris trichiura, 0.3% for Strongyloides stercoralis, and 1.3% for Hymenolepis nana. Over a 1-month time frame, new infections were observed at a rate of 11% for G. duodenalis, 4% for E. histolytica/dispar, 7% for A. lumbricoides, 11% for T. trichiura, 0% for S. stercoralis, and 2% for H. nana. Intestinal symptoms (diarrhoea, vomiting, gas, stomach pain, and loss of appetite) were associated with presence of one or more of C. parvum or B. hominis organisms in stool samples. CONCLUSIONS Intestinal parasitic infections contribute significantly to the enteric disease burden experienced by this group of children. The organisms most strongly implicated by this study are common and difficult-to-treat protozoan pathogens.

This paper presents the analysis of heat transfer in a partially wet annular fin assembly during the process of dehumidification. In past studies, both fully dry and fully wet fins have been analyzed. New analytical formulation leading to a closed-form solution has been developed for a partially wet fin, which is most common in dehumidifier coil operation during air conditioning. The parameters that influenced the heat transfer rate in the finned tube structure are ratio of fin and wall thermal conductivities, ratio of fin thickness to fin pitch, ratio of wall thickness to fin pitch, ratio of fin length to fin pitch, cold fluid Biot number, ambient Biot number, the relative humidity and dry bulb temperature of the incoming air, and the cold fluid temperature inside the coil. Calculations were carried out to study the performance of the heat exchanger. The computed results included the temperature distribution in the wall and the fin and the fin efficiency.

RESUMENObjetivo. El objetivo de este trabajo fue caracterizar en el biomodelo Mesocricetus auratus la sintomatología y lesiones anatomopatológicas que provocan 5 aislados clínicos de Leptospira spp., provenientes de Nicaragua. Materiales y métodos. Con este fin se inocularon 50 hámster por vía i.p con 1mL del cultivo de cada una de las cepas en fase exponencial teniendo una concentración celular de 7.5 x 106 leptospira/mL (10 animales por cepa), evaluándose signos de la enfermedad, mortalidad durante 14 días, lesiones anatomopatológicas macroscópicas y microscópicas mediante tinción con hematoxilina-eosina y tinción de Warthyn Starryn. Resultados. Todas las cepas presentaron alta mortalidad, mostrando un cuadro tanto clínico, como lesional característico de la infección experimental. Además, causaron la muerte al 100% de los animales entre el tercer y décimo día postinfección. En el estudio anatomopatológico la cepa del serogrupo Ballum y la del serogrupo Pomona produjeron focos de hemorragias específicamente en el riñón y pulmones. De forma similar ocurrió una congestión hepática y renal, mientras que la hemorragia renal fue observada con mayor frecuencia en la cepa del serogrupo Pomona, diferenciándose del resto de las cepas que mostraron esta lesión con menos frecuencia. Conclusiones. Este trabajo permitió una mayor caracterización de estas cepas siendo utilizadas como futuras candidatas vacunales frente a una nueva epidemia de Leptospirosis en Nicaragua.

A new high-performance and reduced hardware architecture for the computation of the H.264/AVC forward and inverse quantization operations is presented in this paper. This architecture is based on a highly flexible processing structure that is suitable for very efficient implementations using both FPGA and ASIC technologies. Moreover, it offers several different configurations, in order to provide different trade-offs in terms of performance and hardware cost. Experimental results concerning implementations using a Xilinx Virtex-5 FPGA and a 90 nm CMOS process from UMC demonstrated that the proposed architecture can be used to compute, in real-time, the forward and inverse quantization operations for videos with resolutions up to the Digital Cinema format (4096x2048 @ 30fps).

RESUMENObjetivo. El objetivo de este trabajo fue comparar los índices espontáneos e inducidos en ratones de ambos sexos de las líneas Balb/c, NMRI, OF-1 y C57BL/6/cenp, mediante el ensayo de aberraciones cromosómicas en células de la médula ósea. Materiales y métodos. Con este fin se determinó la línea más eficiente, sobre la base de la aparición significativa de índices espontáneos más bajos e índices inducidos altos a sustancias mutagénicas como la ciclofosfamida (CF). Resultados. Se obtuvo como resultado que la línea Balb/c en ambos sexos difiere significativamente de las demás líneas evaluadas. En esta línea se encontró el menor número de células totales con aberraciones estructurales y un mayor número de inducción de aberraciones cromosómicas cuando es utilizada la CF como mutágeno. Conclusiones. Este trabajo permitirá utilizar la mejor línea de ratones como biomodelo en este ensayo de genotoxicidad, además que le confiere a esta técnica citogenética mayor veracidad y robustez

Human pulmonary and subcutaneous dirofilariosis caused by Dirofilaria immitis and Dirofilaria repens are worldwide diagnosed with increasing frequency. These species are responsible for the development of benign pulmonary and subcutaneous nodules, respectively, that can be confused with lung or cutaneous cancer. The aim of the present work was to identify D. immitis and D. repens proteins differentially recognized by serum samples from individuals with human pulmonary and subcutaneous dirofilariosis, using two-dimensional electrophoresis and mass spectrometry. Twenty-three immunoreactive proteins of D. immitis and 15 of D. repens were identified. The results point to the existence of differential antigenic recognition in each species, both in the number and type of proteins recognized. Individuals with pulmonary dirofilariosis recognized, on the proteome of D. immitis, among others, different isoforms of 6 enzymes involved in glycolysis, 3 redox-related proteins with antioxidant capacity and 3 heat shock proteins. Individuals with subcutaneous dirofilariosis recognized on the proteome of D. repens only 3 glycolytic enzymes, one protein involved in redox processes and one heat shock protein. These data suggest that in cases of pulmonary dirofilariosis there exists a wider recognition of immunoreactive D. immitis proteins related to key survival processes, such as energy generation, the struggle against oxidative stress and molecular repair, than in cases of human subcutaneous dirofilariosis against D. repens. This could contribute to explain the differences described in the capacity of D. immitis and D. repens development and in the frequency of occurrence of pulmonary and subcutaneous dirofilariosis in the human host.

The western mosquitofish (Gambusia affinis affinis) is a useful model for the study of sexual dimorphism and the neural circuits associated with sexual differentiation. This is largely because of its anal fin, which undergoes radical postnatal transformation in males. Understanding the neural mechanisms involved in this process may also help elucidate basic principles of the nervous system. The authors describe the mosquitofish as a model for research and present guidelines for the care and use of this species.

This paper examines the globalization and concentration trends of Puerto Rico’s television market during 2003-2005 periods. The research analyzes contemporary mass media industry leaders in Puerto Rico, as well as, particular attention is given to terrestrial, cable and satellite television industries, and the concentration of market share in the Puerto Rican market. It provides an overview about the displacement of early Puerto Rican television companies by American communication groups, the increase of religious television stations, and the under representation of noncommercial stations in the radio-electric spectrum., El ensayo examina las tendencias de la globalización y la concentración en el mercado de la televisión en Puerto Rico durante el periodo 2003-2005. Se estudian los medios de comunicación líderes en Puerto Rico, particularmente los canales de la televisión terrestre, los operadores de televisión por cable y satélite y los índices de concentración en la cuota del mercado. Desde un enfoque histórico, se discute el desplazamiento de las empresas puertorriqueñas dedicadas a la explotación de la televisión, la posterior hegemonía de los grupos de comunicación norteamericanos en la televisión en Puerto Rico, el crecimiento de los canales religiosos y la infrarepresentación de los canales públicos en la distribución del espectro radioeléctrico.

This paper presents a study of thermal behavior in a refrigerated warehouse equipped with ceiling type refrigeration unit. A two-dimensional steady-state problem was solved by using computational fluid dynamics modeling and simulation. The computational model includes a refrigerated space at the center plane of an array of 4 piles by 3 stacks of palletized product packages with a evaporator fan refrigeration unit, in which the fan pull air through cooling coil and blow out into the space. A parametric analysis was done based on fourteen simulation cases of conditions including different locations of the refrigeration unit as well as different normal forced air velocities produced by the fan. Typical distributions of velocity and temperature are presented. From the results, it is found that better cooling effectiveness and uniformity of the refrigerated space can be achieved by using higher normal supply air speed or locating the refrigeration unit lower and closer to the array of stacks of product packages.Copyright © 2006 by ASME

The aim of this paper is to present a thermodynamic analysis of a magnetic liquefier for hydrogen. A hydrogen liquefaction cycle is examined. A magnetic refrigerator, a liquid-nitrogen pre-cooling system, an expansion valve and a liquid-hydrogen separator integrate the system. The magnetic refrigerator consists of two heat exchangers and two stages of beds of magnetic materials. The analysis considered that the system operates with gaseous hydrogen entering at high pressure and ambient temperature. A fraction of this incoming flow is liquefied by the system. One magnetic material GdNi2 is used in the upper stage and another magnetic material GdPd is used in the lower stage. The heat transfer fluid for the magnetic refrigerator is helium. The beds in both stages are periodically magnetized and demagnetized and the fluid flows are arranged to meet the cycle liquefaction requirements. Sensitivity analysis has been performed to study the thermodynamic behavior of the magnetic liquefier cycle. Liquefaction efficiency, the nitrogen boil-off rate per unit mass of hydrogen, the fraction of the hydrogen gas that is liquefied and the magnetic refrigerator performance trends are evaluated. Simulations indicate that the higher the performance of the magnetic refrigerator is the higher the liquefaction efficiency of the system is with the same intermediate temperature. It was also observed that the liquefaction efficiency increases with the decrease in the nitrogen boil-off rate per unit mass of hydrogen. Magnetic liquefier exhibits a great potential by showing a very high efficiency when compared to small and large scale commercial liquefiers for hydrogen.Copyright © 2005 by ASME

The study of human thermal comfort requires detailed information about distributions of air velocity, air temperature and relative humidity in an occupied zone. Air quality is related to the contaminant distributions and contaminant removal effectiveness in indoor environment. This paper presents an evaluation of thermal comfort and contaminant removal for an office setting with underfloor air distribution system by the use of computational fluid dynamics modeling. A typical single cubicle in a large office floor in steady state condition of airflow as well as heat and mass transfer is investigated for both cooling and heating scenarios. The model includes a typical cubicle in a large office floor with a chair, a desk with a personal computer on its top, and heat sources such as seated people, computer monitor and CPU, and lights. Air enters the occupied zone through an inlet located at the floor level supplying a vertical upward inflow. Five different locations of the inlet diffuser, three different inlet air speeds, and four different loads of heat loss through the floor slab in heating case scenario were considered. Distributions of velocity, temperature, relative humidity, and contaminant concentration in such cases were computed. The results were compared among various simulation cases and showed reasonable agreement with experimental data taken from related literature.

This study considers airflow simulations to evaluate the impact of different window air-conditioner locations on the thermal comfort in an office rooms (OR). This paper compares the air distribution for an office room by using computational fluid dynamics (CFD) modeling. The air distribution was modeled for a typical office room window air conditioning unit, air supply from a high pressure on the top and the low pressure exhaust on the bottom considering the existing manufacturing ratios for surface areas. Calculations were done for steady-state conditions including an occupant and a light source. The discharge angle for the supply grill of the AC unit was varied from 20 to 40 degrees. The position of the air conditioner was also varied and studied at 60%, 75% and 90% of the total height of the room. In addition the location of the occupant within the office room was varied. Predictions of the air movement, room temperature, room relative humidity, comfort level, and distribution of contaminants within the office room are shown. Analysis of these simulations is discussed. The positions of the air-conditioner unit, the inlet angle and the occupant position in the office room have shown to have important impacts on air quality and thermal comfort. Results are in good agreement with available experimental data.

Research on natural environmentally friendly refrigerants is very important especially because the world-wide agreement about restriction in the use of ozone depleting refrigerants. Carbon dioxide is a natural refrigerant that has been considered for certain refrigeration and air conditioning applications. The aim of this paper is to present a thermodynamic analysis of carbon dioxide cycles in order to evaluate the potential performance of a refrigeration cycle using carbon dioxide. A thermodynamic model for the cycle is developed which can simulate the operation of a carbon dioxide refrigeration/AC cycle. This model takes into account the practical effects of the thermo-physical properties of carbon dioxide as refrigerant in a trans-critical cycle. A sensitivity analysis has been conducted so that cycle performance is estimated. The cooling load, compressor power, and coefficient of performance (C.O.P.) were evaluated. One and two stages of compression were also considered for comparison purposes. Cycle performance was evaluated based on variation of important parameters such as evaporator, intermediate, and discharge pressures. The effects of cycle components on system capacity and cycle performance are also investigated. Comparison between performances of the CO2 cycle and the standard vapor compression cycle is performed. Thermodynamic calculations showed reasonable agreement with available experimental data based on the general assumptions made.Copyright © 2005 by ASME

An analysis of a magnetic refrigeration cycle was carried out. The system consists of heat exchangers and beds of magnetic materials. The analysis considered that the system operates near room temperature in a magnetic field between 1 and 5 T and uses 3 kg of gadolinium (Gd) spheres packed in two magnetocaloric beds. The heat transfer fluid is water. The beds are periodically magnetized and demagnetized and the fluid flows are arranged to meet the cycle requirements. Sensitivity analysis has been performed. Cooling power, magnetic field, and temperature span trends are simulated. The cooling and heating effects were estimated based on the magnetocaloric effect of gadolinium. Findings indicate that the higher the magnetic field is the higher the cooling power with the same temperature span. It was also observed that the cooling power decreases with the increase in the temperature span for various magnetic fields. COP vs. temperature span was also considered. The trend indicates that COPactual / COPCarnot decreases with an increase in the temperature span. These trends agreed with those shown by experimental data.Copyright © 2004 by ASME

This paper uses airflow simulations to evaluate different ventilation systems on an operating room (OR). This study compares air distribution systems for an operating room by use of computational fluid dynamics (CFD) modeling. The air supply distribution and exhaust arrangements were modeled for a directional air flow system where air moves across the space from the high-pressure supply area to the low pressure exhaust area. Calculations were done to model a typical operating room in a steady-state condition with inclusion of object such as surgical lights, operating table, heat sources such as surgical staff and a patient, side-wall supply grille and exhaust air grilles. The discharge angle for the side-wall supply grille was varied from 0 to 45 degrees. Air return locations were also studied. One and two air exhaust outlet sites inside the surgical suite were considered. In the two-exhaust outlet configuration, one position was close to the floor and the other position was high on the wall. Simulations with combinations of 1:0, 1:0.343, 0.343:1, and 1:1 flow rates between the two return locations were performed. Predictions for the air movement, room temperature, room relative humidity, and concentration of contaminants within the operating room are shown. Analysis of these predictions is discussed. The supply and exhaust conditions of the ventilation air flow are shown to play an important role in the control of air quality. Results show good agreement with experimental data.Copyright © 2004 by ASME

The performance of the air conditioner was tested in an extensive experimental program using the environmentally controlled chambers in a test facility. Two psychometric rooms provided constant ambient temperature and humidity conditions for a test unit using ASHRAE standard procedures [1]. The indoor and outdoor units were placed into separate environmental chambers, which provided precise temperature, humidity, and airflow conditions for simulation of various operating conditions. The first goal of the experimental program was to define the range of conditions over which the test unit should be tested. The second goal of the experimental studies was to determine the performance of the test unit under the defined conditions. All air conditioner performance data has been collected with air side instrumentation only. Experimental tests were performed using the test unit over a range of outdoor temperatures between 22.4°C (80°F) and 40.6°C (105°F) and indoor temperatures between 18.3°C (65°F) and 35°C (95°F). Analysis of the experimental data was performed by studying air conditioning parameters such as heat rejection rate qc , compressor power W, system capacity qe , and coefficient of performance COP. The analysis was accomplished with the variation of a boundary condition. The sensitivity analysis of experimental data gave expected results when compared to those shown by air conditioning units similar to our test unit.Copyright © 2002 by ASME

A simplified model based on experimental data has been developed for applications in air-conditioning systems simulations. Cycle thermodynamic relationships, along with experimental data, were used to mathematically model the air-conditioning system. Characteristic parameters of the equipment were determined from the results of a limited number of test points. The following parameters were used: the clearance factor C, the piston displacement PD, the efficiency of the compressor ηcomp, the sensible heat factor SHF and the product of the overall heat transfer coefficient times area (UA) for the heat exchangers. Component performance simulation data was validated using experimental data from a 3-ton air conditioner. The model calculates the following parameters: coefficient of performance (COP), system capacity (qe), system heat rejection (qc), and compressor power (W) at any operating condition. The simulation model consists of work and energy balance relationships for the evaporator, condenser, expansion device, and compressor. The model predicted system heat rejection (qc) and system capacity (qe) within 10% of experimental data. The required compressor power (W) was predicted within 5% of uncertainty. However, the coefficient of performance (COP) had an uncertainty slightly higher than ±13% when compared to experimental data. The simulation model can be used as an effective tool for much faster equipment certification minimizing the required number of testing points.