Search for a Neutron Dark Decay in

Neutron dark decays have been suggested as a solution to the discrepancy between bottle and beam experiments, providing a dark matter candidate that can be searched for in halo nuclei. The free neutron in the final state following the decay of ^{6}He into ^{4}He+n+χ provides an exceptionally clean detection signature when combined with a high efficiency neutron detector. Using a high-intensity ^{6}He^{+} beam at Grand Accélérateur National d'Ions Lourds, a search for a coincident neutron signal resulted in an upper limit on a dark decay branching ratio of Br_{χ}≤4.0×10^{-10} (95% C.L.). Using the dark neutron decay model proposed originally by Fornal and Grinstein, we translate this into an upper bound on a dark neutron branching ratio of O(10^{-5}), improving over global constraints by one to several orders of magnitude depending on m_{χ}.

The Atacama Rover Astrobiology Drilling Studies (ARADS) Project.

With advances in commercial space launch capabilities and reduced costs to orbit, humans may arrive on Mars within a decade. Both to preserve any signs of past (and extant) martian life and to protect the health of human crews (and Earth's biosphere), it will be necessary to assess the risk of cross-contamination on the surface, in blown dust, and into the near-subsurface (where exploration and resource-harvesting can be reasonably anticipated). Thus, evaluating for the presence of life and biosignatures may become a critical-path Mars exploration precursor in the not-so-far future, circa 2030. This Special Collection of papers from the Atacama Rover Astrobiology Drilling Studies (ARADS) project describes many of the scientific, technological, and operational issues associated with searching for and identifying biosignatures in an extreme hyperarid region in Chile's Atacama Desert, a well-studied terrestrial Mars analog environment. This paper provides an overview of the ARADS project and discusses in context the five other papers in the ARADS Special Collection, as well as prior ARADS project results.

Impact of Nuclear Deformation and Pairing on the Charge Radii of Palladium Isotopes.

The impact of nuclear deformation can been seen in the systematics of nuclear charge radii, with radii generally expanding with increasing deformation. In this Letter, we present a detailed analysis of the precise relationship between nuclear quadrupole deformation and the nuclear size. Our approach combines the first measurements of the changes in the mean-square charge radii of well-deformed palladium isotopes between A=98 and A=118 with nuclear density functional calculations using Fayans functionals, specifically Fy(std) and Fy(Δr,HFB), and the UNEDF2 functional. The changes in mean-square charge radii are extracted from collinear laser spectroscopy measurements on the 4d^{9}5s ^{3}D_{3}→4d^{9}5p ^{3}P_{2} atomic transition. The analysis of the Fayans functional calculations reveals a clear link between a good reproduction of the charge radii for the neutron-rich Pd isotopes and the overestimated odd-even staggering: Both aspects can be attributed to the strength of the pairing correlations in the particular functional which we employ.

Una vista a la tasa de mortalidad por enfermedad de alzheimer en Chile en el periodo de 2017 a 2021 / A view of the mortality rate due to alzheimer's disease in Chile in the period from 2017 to 2021

Introducción: La enfermedad de Alzheimer (EA) es la principal causa de demencia, caracterizada por pérdida progresiva de memoria. Principal fuente de morbimortalidad en mayores de 65 años. En los últimos 20 años las muertes por EA han aumentado un 145% en el mundo. En Chile no hay estudios actuales que describan mortalidad por EA. El objetivo del presente trabajo es analizar y comparar las tasas de mortalidad (TM) por EA según sexo y grupo etario en Chile entre 2017-2021. Materiales y métodos: Estudio descriptivo, ecológico, sobre defunciones por EA entre 2017-2021 en Chile según sexo y grupo etario (n=10.223). Información obtenida de la base de datos del Departamento de Estadísticas e Información de Salud. Se realizó estadística descriptiva y cálculo de TM. No se requiere comité de ética. Resultados: La máxima TM del periodo fue 11,74 por cada 100.000 habitantes en 2021. El sexo femenino logró la mayor TM en este periodo. El grupo etario con mayor cantidad de defunciones fue el de 81 o más años con 76.6% (7.829) de las defunciones totales. Discusión: Se evidenció mantención y luego ascenso de TM por EA, podría deberse al aumento en la esperanza de vida. La mayor frecuencia de defunciones según sexo y edad, podría explicarse por mayor vulnerabilidad femenina a desarrollar EA y a cambios fisiológicos del envejecimiento. En conclusión, la TM por EA en Chile ha aumentado, probablemente secundario al aumento en la esperanza de vida. Se hace un llamado a continuar el estudio de la patología.

Introduction: Alzheimer's disease (AD) is the most common cause of dementia, characterized by progressive memory loss. It is the main source of morbidity and mortality in individuals over 65 years of age, with age being its primary non-modifiable risk factor. In the last 20 years, deaths from AD have increased by 145% worldwide. However, there are no current studies in Chile that describe mortality from AD. The objective of this study is to analyze and compare mortality rates due to AD according to sex and age group in the Chilean population during the years 2017-2021. Material and Methods: Descriptive, ecological study on deaths from AD between 2017-2021 in Chile, categorized by sex and age group (n=10,223). The database was obtained from the Department of Health Statistics and Information. Descriptive statistics and mortality rate calculations were performed. No ethics committee approval was required. Results: The maximum mortality rate (MR) was observed in 2021 with a value of 11.74 per 100,000 inhabitants. Women had the highest MR in this period. The age group with the highest number of deaths was 81 years or older, accounting for 76.6% (7,829) of the total deaths. Discussion: A plateau and subsequent increase in MR due to AD were observed, possibly explained by the increase in life expectancy. The higher frequency of deaths in women and specific age groups may be attributed to the higher vulnerability of women to developing AD and physiological changes related to aging. In conclusion, the MR from AD has increased in Chile, likely due to the rise in life expectancy, emphasizing the importance of continued research on this pathology.

4D-imaging of drip-line radioactivity by detecting proton emission from 54mNi pictured with ACTAR TPC.

Proton radioactivity was discovered exactly 50 years ago. First, this nuclear decay mode sets the limit of existence on the nuclear landscape on the neutron-deficient side. Second, it comprises fundamental aspects of both quantum tunnelling as well as the coupling of (quasi)bound quantum states with the continuum in mesoscopic systems such as the atomic nucleus. Theoretical approaches can start either from bound-state nuclear shell-model theory or from resonance scattering. Thus, proton-radioactivity guides merging these types of theoretical approaches, which is of broader relevance for any few-body quantum system. Here, we report experimental measurements of proton-emission branches from an isomeric state in 54mNi, which were visualized in four dimensions in a newly developed detector. We show that these decays, which carry an unusually high angular momentum, ℓ = 5 and ℓ = 7, respectively, can be approximated theoretically with a potential model for the proton barrier penetration and a shell-model calculation for the overlap of the initial and final wave functions.

SISTEMA DE GESTIÓN PARA LA INFORMACIÓN DE LOS CANALES ENDÉMICOS

Introducción: los departamentos de Vigilancia Epidemiológica y Análisis en Cuba se encargan de analizar la evolución y tendencias de los brotes o epidemias que inciden en una población. Para detectar la aparición se utilizan métodos y herramientas estadísticos que ayudan a la toma de decisiones; sin embargo, existen limitaciones en el manejo de la información para obtener los pronósticos. Objetivo: describir un sistema de gestión para la información de canales endémicos con la aplicación de herramientas Web para el manejo de información estadística de pronósticos. Métodos: el universo de estudio, está conformado por los 10 especialistas del departamento de Vigilancia Epidemiológica y Análisis de Sancti Spíritus. Se utilizó la observación, la entrevista y la encuesta para obtener información de los profesionales dedicados a esta actividad. El método de Bortman se utilizó para el cálculo de los canales endémicos, el método sistémico en la determinación de las herramientas para el desarrollo del software, la metodología XP en la modelación, definición de las etapas de desarrollo del sistema de gestión y la Norma ISO/IEC 9126 para evaluar la calidad. Resultados: desarrollo de un sistema de gestión para la información de canales endémicos con la aplicación de herramientas Web. Conclusión: se describió el desarrollo de un sistema de gestión como una solución adecuada para mejorar el proceso de elaboración de los canales endémicos. Lo que repercute en un mejor control de enfermedades y la toma de decisiones ante la aparición de posibles epidemias.[AU]

Consequences of excessive plasticity in the hippocampus induced by perinatal asphyxia.

Perinatal asphyxia (PA) is one of the most frequent risk factors for several neurodevelopmental disorders (NDDs) of presumed multifactorial etiology. Dysfunction of neuronal connectivity is thought to play a central role in the pathophysiology of NDDs. Because underlying causes of some NDDs begin before/during birth, we asked whether this clinical condition might affect accurate establishment of neural circuits in the hippocampus as a consequence of disturbed brain plasticity. We used a murine model that mimics the pathophysiological processes of perinatal asphyxia. Histological analyses of neurons (NeuN), dendrites (MAP-2), neurofilaments (NF-M/Hp) and correlative electron microscopy studies of dendritic spines were performed in Stratum radiatum of the hippocampal CA1 area after postnatal ontogenesis. Protein and mRNA analyses were achieved by Western blot and RT-qPCR. Behavioral tests were also carried out. NeuN abnormal staining and spine density were increased. RT-qPCR assays revealed a ß-actin mRNA over-expression, while Western blot analysis showed higher ß-actin protein levels in synaptosomal fractions in experimental group. M6a expression, protein involved in filopodium formation and synaptogenesis, was also increased. Furthermore, we found that PI3K/Akt/GSK3 pathway signaling, which is involved in synaptogenesis, was activated. Moreover, asphyctic animals showed habituation memory changes in the open field test. Our results suggest that abnormal synaptogenesis induced by PA as a consequence of excessive brain plasticity during brain development may contribute to the etiology of the NDDs. Consequences of this altered synaptic maturation can underlie some of the later behavioral deficits observed in NDDs.

Arbolado urbano, calidad del aire y afecciones respiratorias en seis comunas de la provincia de Santiago, Chile / Urban trees, air quality and respiratory diseases in six communes of the province of Santiago, Chile

Ozone (O3) is a secondary pollutant, often above the norm in some areas of Santiago in the spring-summer period. It is formed in the atmosphere by photochemical reactions, between nitrogen oxides (NOx) and volatile organic compounds (VOCs), which have an important biogenic contribution (BVOCs). In this research the interrelationship between urban trees, their contribution to atmospheric ozone formation and particulate matter, and respiratory diseases in 6 communes in the province of Santiago was analyzed. The choice of the communes considered the number of inhabitants, the existence of stations monitoring air quality, the percentage of green areas and the geographical distribution. The results showed correlation between the type of species of urban trees, ozone, particulate matter and respiratory diseases: asthma and pneumonia. Necessity for replacement of exotic trees species by native species is concluded.

El ozono (O3) es un contaminante secundario, frecuentemente sobre la norma en algunas áreas de Santiago en el período primavera-verano. Se forma en la atmósfera por reacciones fotoquímicas, a partir de óxidos de nitrógeno (NOx) y compuestos orgánicos volátiles (COVs), los cuales tienen un aporte biogénico (COVsB) importante. En esta investigación se analizó la interrelación entre el arbolado urbano, su contribución a la formación de ozono y material particulado atmosféricos, y las afecciones respiratorias en 6 comunas de la provincia de Santiago. La elección de las comunas consideró el número de habitantes, la existencia de estaciones de monitoreo de calidad del aire, el porcentaje de áreas verdes y la distribución geográfica. Los resultados muestran que existe relación entre el tipo de especies del arbolado urbano, el ozono, el material particulado y las enfermedades respiratorias: asma y neumonía. Se concluye la necesidad de considerar el remplazo de especies exóticas por especies nativas.

Repellent and Attractive Effects of α-, ß-, and Dihydro-ß- Ionone to Generalist and Specialist Herbivores.

In plants, the oxidative cleavage of carotenoid substrates produces volatile apocarotenoids, including α-ionone, ß-ionone, and dihydro-ß-ionone, compounds that are important in herbivore-plant communication. For example, ß-ionone is part of an induced defense in canola, Brassica napus, and is released following wounding by herbivores. The objectives of the research were to evaluate whether these volatile compounds would: 1) be released in higher quantities from plants through the over-expression of the carotenoid cleavage dioxygenase1 (CCD1) gene and 2) cause herbivores to be repelled or attracted to over-expressing plants relative to the wild-type. In vivo dynamic headspace collection of volatiles coupled with gas chromatography-mass spectrometry was used to determine volatile organic compounds (VOC) in the headspace of the Arabidopsis thaliana ecotype Columbia-0 (L.) over-expressing the AtCCD1 gene. The analytical method allowed the detection of ß-ionone in the Arabidopsis headspace where emission rates ranged between 2 and 5-fold higher compared to the wild type, thus corroborating the in vivo enhancement of gene expression. A two chamber choice test between wild type and AtCCD1 plants revealed that crucifer flea beetle Phyllotreta cruciferae (Goeze) adults were repelled by the AtCCD1 plants with the highest transcription and ß-ionone levels. α-Ionone and dihydro-ß-ionone were not found in the headspace analysis, but solutions of the three compounds were tested in the concentration range of ß-ionone found in the Arabidopsis headspace (0.05 to 0.5 ng/µl) in order to assess their biological activity with crucifer flea beetle, two spotted spider mite Tetranychus urticae (Koch), and silverleaf whiteflies Bemisia tabaci (Gennadius). Choice bioassays demonstrated that ß-ionone has a strong repellent effect toward both the flea beetle and the spider mite, and significant oviposition deterrence to whiteflies. In contrast, dihydro-ß-ionone had attractant properties, especially to the crucifer flea beetle, while α-ionone did not show any significant activity. These findings demonstrate how regulating genes of the carotenoid pathway can increase herbivore deterrent volatiles, a novel tool for insect pest management.

The modern, hybrid total hip arthroplasty for primary osteoarthritis at the Hospital for Special Surgery.

We describe our technique and rationale using hybrid fixation for primary total hip arthroplasty (THA) at the Hospital for Special Surgery. Modern uncemented acetabular components have few screw holes, or no holes, polished inner surfaces, improved locking mechanisms, and maximised thickness and shell-liner conformity. Uncemented sockets can be combined with highly cross-linked polyethylene liners, which have demonstrated very low wear and osteolysis rates after ten to 15 years of implantation. The results of cement fixation with a smooth or polished surface finished stem have been excellent, virtually eliminating complications seen with cementless fixation like peri-operative femoral fractures and thigh pain. Although mid-term results of modern cementless stems are encouraging, the long-term data do not show reduced revision rates for cementless stems compared with cemented smooth stems. In this paper we review the conduct of a hybrid THA, with emphasis on pre-operative planning, surgical technique, hypotensive epidural anaesthesia, and intra-operative physiology.

Carcinoma adenoide quístico traqueal en un paciente con tos crónica / No disponible

El carcinoma adenoide quístico es una neoplasia traqueal primaria poco frecuente cuya histología es la segunda más común después del carcinoma de células escamosas. Los síntomas están usualmente en relación con obstrucción de la vía aérea e incluyen estridor, hemoptisis, disnea y sibilancias. Muchos de estos pacientes son diagnosticados incorrectamente durante meses o años como bronquitis crónica o asma hasta que la lesión se diagnostica. Presentamos un caso de un paciente de 35 años estudiado por tos de seis meses de evolución con carcinoma adenoide quístico traqueal. La exploración física fue normal. La radiografía de tórax mostró una ligera impronta sobre la luz traqueal. La tomografía computarizada y la fibrobroncoscopia con biopsia aportaron el diagnóstico definitivo

Adenoid cystic carcinoma is an infrequent primary tracheal tumor that is second most common tracheal malignancy at histology after squamous cell carcinoma. Symptoms are usually related to airway obstruction including stridor, hemoptysis, shortness of breath and wheezing respiration. Patients may be incorrectly diagnosed and treated for chronic bronchitis or asthma for months or years before the lesion is detected. We present a 35-years-old patient with a 6-month history of cough diagnosed with adenoid cystic carcinoma. General physical examination did not reveal any significant abnormality. Chest radiograph demonstrated a slight narrowing of the tracheal air column. Computed tomography and fibrobronchoscopy with biopsy allowed the final diagnosis

Hindered Gamow-Teller decay to the odd-odd N=Z (62)Ga: absence of proton-neutron T=0 condensate in A=62.

Search for a new kind of superfluidity built on collective proton-neutron pairs with aligned spin is performed studying the Gamow-Teller decay of the T=1, J(π)=0+ ground state of (62)Ge into excited states of the odd-odd N=Z nucleus (62)Ga. The experiment is performed at GSI Helmholtzzentrum für Shwerionenforshung with the (62)Ge ions selected by the fragment separator and implanted in a stack of Si-strip detectors, surrounded by the RISING Ge array. A half-life of T1/2=82.9(14) ms is measured for the (62)Ge ground state. Six excited states of (62)Ga, populated below 2.5 MeV through Gamow-Teller transitions, are identified. Individual Gamow-Teller transition strengths agree well with theoretical predictions of the interacting shell model and the quasiparticle random phase approximation. The absence of any sizable low-lying Gamow-Teller strength in the reported beta-decay experiment supports the hypothesis of a negligible role of coherent T=0 proton-neutron correlations in (62)Ga.

Neumonía lipoidea: A propósito de un caso / No disponible

La neumonía lipoidea es una enfermedad respiratoria poco frecuente, secundaria a la aspiración de materiales oleosos o bien por la liberación de lípidos desde los alvéolos destruidos por diferentes causas. La exposición crónica a sustancias grasas puede pasar inadvertida y producir síntomas respiratorios inespecíficos. Presentamos un caso de neumonía lipoidea crónica exógena en el que no se halló la sustancia de exposición, pero ante la densidad grasa de los infiltrados del TC y la ausencia de otras etiologías posibles se llegó al diagnóstico

Lipoid pneumonia is a rare respiratory disease, secondary to oil substances inhalation or by leakage of lipids of the alveolus cells which are destroyed in different causes. Chronic exposure to fatty substances can remain unnoticed and produce nonspecific respiratory symptoms. We present a case of chronic exogenous lipoid pneumonia in which case the causal agent were not found, but the fat density of the infiltrates in the TC and the absence of other etiologies allowed for the diagnosis

Measurement of the isoscalar monopole response in the neutron-rich nucleus 68Ni.

The isoscalar monopole response has been measured in the unstable nucleus (68)Ni using inelastic alpha scattering at 50A MeV in inverse kinematics with the active target MAYA at GANIL. The isoscalar giant monopole resonance (ISGMR) centroid was determined to be 21.1 ± 1.9 MeV and indications for a soft monopole mode are provided for the first time at 12.9 ± 1.0 MeV. Analysis of the corresponding angular distributions using distorted-wave-born approximation with random-phase approximation transition densities indicates that the L = 0 multipolarity dominates the cross section for the ISGMR and significantly contributes to the low-energy mode. The L=0 part of this low-energy mode, the soft monopole mode, is dominated by neutron excitations. This demonstrates the relevance of inelastic alpha scattering in inverse kinematics in order to probe both the ISGMR and isoscalar soft modes in neutron-rich nuclei.

Half-life systematics across the N=126 shell closure: role of first-forbidden transitions in the ß decay of heavy neutron-rich nuclei.

This Letter reports on a systematic study of ß-decay half-lives of neutron-rich nuclei around doubly magic (208)Pb. The lifetimes of the 126-neutron shell isotone (204)Pt and the neighboring (200-202)Ir, (203)Pt, (204)Au are presented together with other 19 half-lives measured during the "stopped beam" campaign of the rare isotope investigations at GSI collaboration. The results constrain the main nuclear theories used in calculations of r-process nucleosynthesis. Predictions based on a statistical macroscopic description of the first-forbidden ß strength reveal significant deviations for most of the nuclei with N<126. In contrast, theories including a fully microscopic treatment of allowed and first-forbidden transitions reproduce more satisfactorily the trend in the measured half-lives for the nuclei in this region, where the r-process pathway passes through during ß decay back to stability.

Observation of the ß-delayed γ-proton decay of (56)Zn and its impact on the Gamow-Teller strength evaluation.

We report the observation of a very exotic decay mode at the proton drip line, the ß-delayed γ-proton decay, clearly seen in the ß decay of the T_{z}=-2 nucleus ^{56}Zn. Three γ-proton sequences have been observed after the ß decay. Here this decay mode, already observed in the sd shell, is seen for the first time in the fp shell. Both γ and proton decays have been taken into account in the estimation of the Fermi and Gamow-Teller strengths. Evidence for fragmentation of the Fermi strength due to strong isospin mixing is found.

Experimental study of the two-body spin-orbit force in nuclei.

Energies and spectroscopic factors of the first 7/2-, 3/2-, 1/2-, and 5/2- states in the (35)Si21 nucleus were determined by means of the (d, p) transfer reaction in inverse kinematics at GANIL using the MUST2 and EXOGAM detectors. By comparing the spectroscopic information on the Si35 and S37 isotones, a reduction of the p3/2-p1/2 spin-orbit splitting by about 25% is proposed, while the f7/2-f5/2 spin-orbit splitting seems to remain constant. These features, derived after having unfolded nuclear correlations using shell model calculations, have been attributed to the properties of the two-body spin-orbit interaction, the amplitude of which is derived for the first time in an atomic nucleus. The present results, remarkably well reproduced by using several realistic nucleon-nucleon forces, provide a unique touchstone for the modeling of the spin-orbit interaction in atomic nuclei.

Pharmacological alterations that could underlie radiation-induced changes in associative memory and anxiety.

It is widely known that ionizing radiation is a physical agent broadly used to kill tumor cells during human cancer therapy. Unfortunately, adjacent normal tissues can concurrently undergo undesirable cell injury. Previous data of our laboratory demonstrated that exposure of developing rats to ionizing radiations induced a variety of behavioral differences respect to controls, including changes in associative memory and in anxiety state. However, there is a lack of data concerning modifications in different related pharmacological intermediaries. Therefore, the aim of the present study was to investigate whether the behavioral differences observed in young animals irradiated at birth might be underlain by early changes in PKCß1 levels which, in turn, could lead to changes in hippocampal GABAergic neurotransmission. Male Wistar rats were irradiated with 5Gy of X rays between 24 and 48 h after birth. Different pharmacological markers related to the affected behavioral tasks were assessed in control and irradiated hippocampus at 15 and 30 days, namely GABAA receptor, GAD65-67, ROS and PKCß1. Results showed that all measured parameters were increased in the hippocampus of 30-days-old irradiated animals. In contrast, in the hippocampus of 15-days-old irradiated animals only the levels of PKCß1 were decreased. These data suggest that PKCß1 might constitute a primary target for neonatal radiation damage on the hippocampus. Therefore, it could be hypothesized that an initial decrease in the levels of this protein can trigger a subsequent compensatory increase that, in turn, could be responsible for the plethora of biochemical changes that might underlie the previously observed behavioral alterations.