Progress toward the Definition of X-ray Computed Tomography Accuracy in the Characterization of Polymer-Based Lattice Structures.

Lattice structures have become an innovative solution for the improvement of part design, as they are able to substitute solid regions, maintain mechanical capabilities, and reduce material usage; however, dimensional quality control of these geometries is challenging. X-ray computed tomography (XCT) is the most suitable non-destructive metrological technique as it is capable of characterizing internal features and hidden elements. Uncertainty estimation of XCT is still in development, and studies typically use high-resolution calibrated devices such as focal variation microscopes (FVMs) as a reference, focusing on certain parts of the lattice but not the whole structure. In this paper, an estimation of the accuracy of XCT evaluation of a complete lattice structure in comparison to a higher-resolution reference device (FVM) is presented. Experimental measurements are taken on ad hoc designed test objects manufactured in polyamide 12 (PA12) using selective laser sintering (SLS), optimized for the evaluation on both instruments using different cubic-based lattice typologies. The results confirm higher precision on XCT evaluation in both qualitative and quantitative analysis. Even with a lower resolution, XCT is able to characterize details of the surface such as re-entrant features; as well, standard deviations and uncertainties in strut diameter evaluation remain more stable in all cells in XCT, identifying on the other hand reconstruction problems on FVM measurements. Moreover, it is shown that, using XCT, no additional evaluation errors were found in inner cells, suggesting that the measurement of external elements could be representative of the whole structure for metrological purposes.

Use of Cultivated Epidermal Allograft in Chronic Wounds: A Novel Therapeutic Alternative.

Introduction: Chronic wounds represent a frequent cause of consultation for plastic and reconstructive surgeons. The use of epidermal culture stands out because they provide complete epithelialization, adequate aesthetic-functional results, and no morbidity for the patient. Epifast® is a pre-manufactured cultured epidermal allograft derived from the amplification in vitro of human keratinocytes. Materials and Methods: A prospective longitudinal multicenter study was carried out in four chronic wound reference centers, which were in charge of plastic and reconstructive surgery services. For a standardized wound bed preparation, the protocol synthesized by the acronym "TIME" was used. At the end of the "TIME" protocol, the pre-fabricated allograft was applied and removed 7 days after its application. Results: A total of 133 patients with diagnosis of chronic wound were included in the study. The median age was 69.3 ± 13.6 years. The most common comorbidity found was diabetes mellitus type 2 in 71.4% of the patients (n = 95) and systemic arterial hypertension in 60.2% of the patients (n = 80). The most frequent location of chronic wounds was seen in the lower extremity with 45.1% (n = 60). The mean duration for it to close was 46 ± 14 days, in which they closed within the first 3 months in 93% (n = 125) of the cases. About 91.7% (n = 122) of the wounds achieved total closure. Conclusion: Cultured epidermal allograft, combined with a meticulous technique and an adequate selection of patients, represents a safe and effective tool for chronic wounds.

Effects of variable durations of food availability on interval time-place learning with pigeons Columba Livia.

We assessed the effects of variable durations of food availability on an interval time-place learning task. 3 pigeons were exposed to a task in which food could be obtained for responses in one of four feeders according to an RI 25 s during 3 min, after which, food could be obtained on a different feeder according to the same schedule. The correct feeder changed following a fixed sequence that was repeated four times throughout the session. After 50 training sessions, an Open Hopper Test was conducted, after which, the second training condition ensued. This condition was like the first one with the exception that the availability period could be either 1,2,3, or 6 min long. A second test was conducted after 50 sessions of this training. Another group of 3 birds experienced these conditions in the reverse order. Data suggest that birds solved the task via interval timing under the fixed duration condition, and via ordinal timing when faced with variable durations. Birds learned the fixed sequence involved in the task under both conditions. Although the present data agree with previous research exploring variability in TPL tasks, they do not necessarily support previous claims for an asymmetrical role of spatial and temporal information in these tasks.

Bilateral Fascia Lata Flap: An Alternative for Massive Abdominal Wall Defect Repair.

The abdominal wall represents a unique structure of dermo-myotendinous conformation that is considered a surgical challenge. The musculocutaneous pedicled flap, using tensor fasciae latae muscle (TFL), is a technique of abdominal wall repair, and it is becoming a more frequent reconstructive procedure. It is a well-suited procedure because it provides both a semirigid fascia layer and adequate skin coverage. We present a case of a 61-year-old man with the diagnosis of squamous cell carcinoma of the bladder, clinical stage IV (T4bN1M1), complicated with an ileo-recal-urethrocutaneous fistula. We reconstructed a massive defect of the abdominal wall by rotating bilateral pedicled TFL flaps. The therapeutic plan comprised 2 surgical procedures. The first surgical intervention was intended to obtain and temporarily fix the flap, and to allow the delay phenomenon to occur. Three weeks later, we performed the abdominal wall reconstruction by repositioning the bilateral TFL flaps and placing a dual prolene with regenerated oxidized cellulose mesh. We performed a successful palliative procedure in a terminal oncologic patient. Combined with a massive oncologic procedure (done by the oncologic surgeon), we were able to solve the cutaneous fistula and provided a significant improvement in the quality of life. The patient was discharged with no procedure-related complications. He has remained healthy 18 months after surgery, and there has been no evidence of ventral hernia. Bilateral TFL flaps represent a viable alternative for primary or secondary abdominal wall reconstruction in selected cases. This reconstructive strategy should be considered when plastic and reconstructive surgeon faces large and complex abdominal wall defects, associated with significant lack of skin cover.

Ovarian cholesterol efflux: ATP-binding cassette transporters and follicular fluid HDL regulate cholesterol content in mouse oocytes†.

High density lipoproteins (HDL) take up cholesterol from peripheral tissues via ABC transporters and deliver it to the liver via scavenger receptor class B type I (SR-B1). HDL are the main lipoproteins present in follicular fluid (FF). They are thought to derive from plasma, but their origin is still controversial. SR-B1 knock-out (KO) mice have provided important evidence linking HDL metabolism and female fertility. These mice have cholesterol-rich circulating HDL and female infertility that can be restored by treating mice with the cholesterol-lowering drug probucol. Ovulated oocytes from SR-B1 KO females are dysfunctional and show excess cholesterol. The mechanisms explaining the contribution of FF HDL to oocyte cholesterol homeostasis are unknown. Here, using quantitation of filipin fluorescence we show that in SR-B1 KO ovaries, cholesterol excess is first observed in immature oocytes in antral follicles. By performing cross-transplant experiments between WT and apolipoprotein A-I deficient (ApoA-I KO) mice, which lack the main protein component of HDL, we provide evidence supporting the plasmatic origin of FF HDL. Also, we demonstrate that probucol treatment in SR-B1 KO females results in lowering of cholesterol content in their oocytes. Incubation of oocytes from SR-B1 KO mice with purified WT HDL reduces their cholesterol content, suggesting that HDL promote efflux of excess cholesterol from oocytes. In agreement with this hypothesis, we identified ABC transporters in oocytes and observed that ABCA1 KO oocytes have excess cholesterol and lower viability than WT oocytes.

Evidence of non-circadian timing in a low response-cost daily Time-Place Learning task with pigeons Columba Livia.

Previous research has shown that rats require high response cost in order to display circadian timing in daily Time-Place Learning (TPL) tasks. For many possible reasons, no explicit effort to explore the effects of response cost on the performance of other species in these tasks has been made. Therefore, the present paper explores the effects of response cost on pigeon's performance on a daily TPL task. Head entry responses were reinforced according to a Random Interval schedule of reinforcement on one feeder during morning sessions and on another feeder during afternoon sessions. Feeders were located 8 cm apart for one group of birds (Group Near) and 56 cm apart for another group (Group Far). After 50 training sessions, testing began. Test sessions consisted of skipping either the morning or the afternoon session. Results show that most birds in the near group respond primarily on the opposite feeder during the first 20 s of the test sessions and then they switch to the correct feeder. On the other hand, most birds in Group Far respond at the same rate on both opposite and correct feeders during 20 s, and then they respond primarily on the correct feeder. The possibility of these data revealing non circadian timing for birds in a low response-cost daily TPL task is discussed along with the implications of such a finding for previous literature that claims that this type of performance could be unique to rats.

Nonlinear Self-Action of Light through Biological Suspensions.

It is commonly thought that biological media cannot exhibit an appreciable nonlinear optical response. We demonstrate, for the first time to our knowledge, a tunable optical nonlinearity in suspensions of cyanobacteria that leads to robust propagation and strong self-action of a light beam. By deliberately altering the host environment of the marine bacteria, we show experimentally that nonlinear interaction can result in either deep penetration or enhanced scattering of light through the bacterial suspension, while the viability of the cells remains intact. A theoretical model is developed to show that a nonlocal nonlinearity mediated by optical forces (including both gradient and forward-scattering forces) acting on the bacteria explains our experimental observations.

Assessing the acquisition of anticipatory responding in the pigeon using reaction time.

We report a novel method for investigating the acquisition of anticipatory responding in the pigeon. Four pigeons (Columba livia) received food for pecking a starburst target stimulus displayed in the bottom-left or bottom-right portion of a computer screen. The target stimulus was preceded by 1 of 3 fractal images displayed in either the upper-left or upper-right portion of the screen: 1 of the fractals was perfectly correlated with the target appearing in the bottom-left, the second fractal was perfectly correlated with the target appearing in the bottom-right, and the third fractal was uncorrelated with the location of the target. The pigeons learned to anticipate the location of the upcoming target stimulus, because they were faster to peck the target stimulus on trials that involved a predictive fractal than on trials that involved a nonpredictive fractal. In a later phase, we reversed the signaled target location of each of the 2 predictive fractals. After an initial disruption in performance, the pigeons successfully learned the new stimulus assignments, exhibiting the same pattern of responding as during the initial training phase. Overall, the results document the utility of this novel training procedure and further underscore the role that associative processes play in anticipatory responding. (PsycINFO Database Record

Vortex degeneracy lifting and Aharonov-Bohm-like interference in deformed photonic graphene.

Photonic graphene, a honeycomb lattice of evanescently coupled waveguides, has provided a superior platform for investigating a host of fundamental phenomena such as unconventional edge states, synthetic magnetic fields, photonic Landau levels, Floquet topological insulators, and pseudospin effects. Here, we demonstrate both experimentally and numerically, topological vortex degeneracy lifting and Aharonov-Bohm-like interference from local deformation in a photonic honeycomb lattice. When a single valley is excited, lattice deformation leads to the generation of a vortex pair due to the lifting of degeneracy associated with pseudospin states. In the case of double-valley excitation, we observe the Aharonov-Bohm-like interference merely due to the deformation of the graphene lattice, which gives rise to an artificial gauge field. Our results may provide insight into the understanding of similar phenomena in other graphene-like materials and structures.

Effects of variable sequences of food availability on interval time-place learning by pigeons.

The effects of within session variability of the sequences of food availability in a 16 period Time Place Learning (TPL) task on the performance of pigeons were assessed. Two groups of birds were exposed to two conditions. For group 1 (N=3), the first condition consisted of a TPL task in which food could be obtained according to a Random Interval (RI) 25s schedule of reinforcement in one of four feeders, the correct feeder changed every 3min. The same sequence was repeated four times within every training session (Fixed Sequence). The second condition was exactly the same as the first one with the exception that the sequence in which the correct feeder changed was randomized, yielding a total of four randomized sequences of food availability each session (Variable Sequence). An Open Hopper Test (OHT) was conducted at the end of each condition. Birds in group 2 (N=3) experienced the same conditions but in the reverse order. Results showed high percent correct responses for both group of birds under both conditions. However, birds were able to time the availability period's duration only under the Fixed Sequence condition, as shown by anticipation, anticipation of depletion and persistence of visiting patterns on the OHT. The implications of these results to Gallistels (1990) tripartite time-place-event memory code model are discussed, pointing out that these results are in line with previous findings about the important role that spatial parameters of a TPL task can play, for accurate timing was precluded when a variable sequence was employed.

[Respiratory day hospital care for immunocompetent adult patients with community-acquired pneumonia]. / Hospitalización diurna como modelo de atención de salud en pacientes adultos inmunocompetentes con neumonía adquirida en la comunidad.

BACKGROUND: Day hospitals can reduce health care costs without increasing the risks of patients with lower respiratory tract infection. AIM: To report the experience of a respiratory day hospital care delivered to adult patients with community-acquired pneumonia (CAP) in a public hospital. MATERIAL AND METHODS: During the fall and winter of 2011 and 2012, adult patients with CAP of intermediate risk categories were assessed in the emergency room, their severity was stratified according to confusion, respiratory rate, blood pressure, 65 years of age or older (CRB-65) score and the Chilean CAP Clinical Guidelines, and were admitted to the respiratory day hospital. RESULTS: One hundred seventeen patients aged 67 ± 16 years, (62% females) with CAP were attended in the respiratory day hospital. Ninety percent had comorbidities, especially chronic obstructive pulmonary disease in 58%, heart disease in 32%, diabetes in 16% and asthma in 13%. Their most important risk factors were age over 65 years in 60%, comorbidities in 88%, failure of antibiotic treatment in 17%, loss of autonomy in 21%, vital sign abnormalities in 60%, mental confusion in 5%, multilobar CAP in 23%, pleural effusion in 15%, hypoxemia in 41% and a serum urea nitrogen over 30 mg/dL in 16%. Patients stayed an average of seven days in the day hospital with oxygen, hydration, chest physiotherapy and third-generation cephalosporins (89%) associated with quinolones (52%) or macrolides (4%). Thirteen patients required noninvasive ventilation, eight patients were hospitalized because of clinical deterioration and three died in hospital. CONCLUSIONS: Day hospital care reduced hospital admission rates of patients with lower respiratory tract infections.

Unveiling pseudospin and angular momentum in photonic graphene.

Pseudospin, an additional degree of freedom inherent in graphene, plays a key role in understanding many fundamental phenomena such as the anomalous quantum Hall effect, electron chirality and Klein paradox. Unlike the electron spin, the pseudospin was traditionally considered as an unmeasurable quantity, immune to Stern-Gerlach-type experiments. Recently, however, it has been suggested that graphene pseudospin is a real angular momentum that might manifest itself as an observable quantity, but so far direct tests of such a momentum remained unfruitful. Here, by selective excitation of two sublattices of an artificial photonic graphene, we demonstrate pseudospin-mediated vortex generation and topological charge flipping in otherwise uniform optical beams with Bloch momentum traversing through the Dirac points. Corroborated by numerical solutions of the linear massless Dirac-Weyl equation, we show that pseudospin can turn into orbital angular momentum completely, thus upholding the belief that pseudospin is not merely for theoretical elegance but rather physically measurable.

Human strategies for solving a time-place learning task: the role of counting and following verbal cues.

Two experiments were conducted to assess the emergence of time-place learning in humans. In experiment 1, a computer based software was designed in which participants had to choose to enter one of four rooms in an abandoned house search for a zombie every 3-15s. Zombies could be found in only one of these rooms every trial in 3 min periods during the 12 min sessions. After 4 training sessions, participants were exposed to a probe session in which zombies could be found in any room on every trial. Almost all participants behaved as if they were timing the availability intervals: they anticipated the changes in the location of the zombie and they persisted in their performance patterns during the probe session; however, verbal reports revealed that they were counting the number of trials in each period in order to decide when to switch between rooms. In the second experiment, the task was modified in two ways: counting was made harder by using three different intertrial ranges within each session: 2-6s, 2-11s and 2-16s. Second, labels were displaced during the final session to assess whether participants learned to click on a given place or to follow a set of verbal cues. We found that participants did not notice the label changes suggesting that they learned to click on a given place, and that a win/stay-lose/shift strategy was clearly used to decide when to switch rooms in the second experiment. The implications of verbal behavior when assessing time-place learning with humans and the possible differences in this process between humans and animals are discussed.

Elimination of transverse instability in stripe solitons by one-dimensional lattices.

We demonstrate theoretically and experimentally that the transverse instability of coherent soliton stripes can be greatly suppressed or totally eliminated when the soliton stripes propagate in a one-dimensional photonic lattice under self-defocusing nonlinearity.

Neospora caninum: Detección de ADN en sangre durante la primera gestación de vaquillas infectadas naturalmente / Neospora caninum: DNA detection in blood during first gestation of naturally infected heifers

The aim of the study was to detect the DNA presence of N. caninum in naturally infected animals, at two moments of their first gestation and at parturition, as well as to record the presentation of abortions. Twenty females between 12 to 14 months of age, seropositive to ELISA test, were selected from a dairy farm with presence of this parasitosis. The females were artificially inseminated and blood samples were taken in the first and second third of gestation and during parturition; DNA was isolated and it was analyzed by a single tube nested PCR with specific primers. In the sampling corresponding to the first third of gestation, 7/20 positive cases were observed (35%), in the second 15/20 (75%) and during parturition 10/20 positive cases (50%). From the total of the animals included in this study, three stayed negative to the test in the three samplings (15%), four were always positive (20%), eight were positive in the second sampling but negative in first (40%) and five were positive in the second and negative in first and the third sampling (25%). All animals remained seropositive during the study; four aborted in the last third of gestation. All the live born calves were seropositive to N. caninum.

El objetivo del trabajo fue detectar la presencia de ADN de N. caninum en animales infectados naturalmente, en dos tiempos de su primera gestación y al parto, así como registrar la presentación de abortos. Se seleccionó, en un establo, con presencia de parasitosis, un lote de 20 hembras de entre 12 y 14 meses de edad, seropositivas en ELISA, las hembras fueron inseminadas artificialmente y se tomaron muestras de sangre en el primero y segundo tercios de gestación y al parto; se aisló ADN y se sometió a PCR anidado en un solo tubo con iniciadores específicos. En el muestreo correspondiente al primer tercio de la gestación, se observaron 7/20 casos positivos (35%), en el segundo 15/20 (75%) y al parto 10/20 casos positivos (50%). De los animales incluidos en el estudio, tres se mantuvieron negativos a la prueba en los tres muestreos (15%), cuatro fueron siempre positivos (20%), ocho fueron positivos en el segundo muestreo pero negativos en el primero (40%) y cinco fueron positivos en el segundo y negativos en el primero y tercero muestreos (25%). No se presentó seroconversión en ningún animal durante el estudio; cuatro de ellos presentaron aborto en el último tercio de gestación. Todas las crías nacidas vivas resultaron seropositivas a N. caninum.