Perturbative analysis of generalized Einstein's theories

The hypothesis that the energy-momentum tensor of ordinary matter is not conserved separately, leads to a non-adiabatic expansion and, in many cases, to an Universe older than usual. This may provide a solution for the entropy and age problems of the Standard Cosmological Model. We consider two different theories of this type, and we perform a perturbative analysis, leading to analytical expressions for the evolution of gravitational waves, rotational modes and density perturbations. One of these theories exhibits satisfactory properties at this level, while the other one should be discarded.Comment: 14 pages, Latex fil

Olive mill wastewater valorization : use by non-conventional yeasts.

peer reviewedThe ability of the strains Yarrowia lipolytica and Candida rugosa to grow on Olive Mill Wastewater (OMW) based medium and to produce high-value compounds from OMW (such as enzymes), while degrading this waste, was tested. Factors affecting cellular growth and OMW degradation were also studied, such as OMW composition, dilution and supplementation. OMW collected from 3-phase olive mill of the north region of Portugal were used and characterized chemical and biochemically. OMW with COD ranging from 100 g·L-1 to 200 g·L-1 were supplemented with yeast extract and ammonium chloride proportionally to its organic composition. Preliminary studies of OMW consumption were carried out in batch cultures of Y. lipolytica W29 and C. rugosa PYCC 3238. The strains were able to grow in the OMW used without dilution, to consume almost all of the sugars present in the media and to significantly reduce COD. Y. lipolytica W29 was less affected by operating conditions changes such as, stirring rate variation and OMW medium supplementation

Experimental and theoretical evidences for the ice regime in planar artificial spin ices

In this work, we explore a kind of geometrical effect in the thermodynamics of artificial spin ices (ASI). In general, such artificial materials are athermal. Here, We demonstrate that geometrically driven dynamics in ASI can open up the panorama of exploring distinct ground states and thermally magnetic monopole excitations. It is shown that a particular ASI lattice will provide a richer thermodynamics with nanomagnet spins experiencing less restriction to flip precisely in a kind of rhombic lattice. This can be observed by analysis of only three types of rectangular artificial spin ices (RASI). Denoting the horizontal and vertical lattice spacings by a and b, respectively, then, a RASI material can be described by its aspect ratio $\gamma$=a/b. The rhombic lattice emerges when $\gamma$=$\sqrt{3}$. So, by comparing the impact of thermal effects on the spin flips in these three appropriate different RASI arrays, it is possible to find a system very close to the ice regime

Vulvar Tuberculosis-A Rare Manifestation of the Disease

Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. According to data from the World Health Organization, this disease remains one of the leading causes of death worldwide. Although it most commonly affects the lungs, tuberculosis can compromise any organ. The present study reports a rare case of vulvar tuberculosis in a postmenopausal woman with a history of asymptomatic pulmonary and pleural tuberculosis, with no prior documented contact with the bacillus. Diagnosis was based on vulvar lesion biopsies, with histological findings suggestive of infection and isolation of M. tuberculosis by microbiological culture and polymerase chain reaction (PCR) essays. The lesions reverted to normal after tuberculostatic therapy.info:eu-repo/semantics/publishedVersio

Food Insecurity Levels among University Students: A Cross-Sectional Study

Background: University students may be vulnerable to food insecurity (FI) due to limited financial resources, lower purchasing power, and increasing housing and food costs. This study aimed to assess the prevalence and severity of FI and its associated factors among university students attending a public Portuguese university. Methods: A cross-sectional survey was designed, and data were collected using a self-reported online questionnaire validated for the Portuguese population. The study population included students from all levels of study and the assessments were conducted during the winter semester (December 2021 to February 2022). Chi-square tests were used to determine the associations between FI and sociodemographic variables. Bivariate logistic regression was further used to assess factors associated with FI. Results: From the 284 participants, 17.3% of students were classified as food insecure, consisting of 14.1% with mild FI, 2.1% with moderate FI, and 1.1% with severe FI. FI was significantly associated with nationality (p = 0.028) and the number of unemployed household members (p = 0.001). In comparison to Portuguese students, students of other nationalities were 4.1 times more likely to be food insecure (OR = 4.089, 95% CI:1.057–15.821, p = 0.041). Students in households with a higher number of members (OR = 2.537, 95% CI:1.231–5.230, p = 0.012) and a higher number of unemployed members (OR = 3.192, 95% CI:1.681–6.059, p < 0.001) were also 2.5 and 3.1 times more likely, respectively, to be food insecure. Conclusions: This study provides an insight into the FI levels of university students in a Portuguese university. Further future studies are needed to use objective measures of food insecurity (availability, access, and utilization of food) and explore interventions addressing food insecurity in this population. © 2022 by the authors.The CECAV is supported by FCT/UIDB/CVT/00772/2020. The CITAB is supported by FCT/UIDB/04033/2020

Magnetic phase transitions in Ta/CoFeB/MgO multilayers

We study thin films and magnetic tunnel junction nanopillars based on Ta/Co$_{20}$Fe$_{60}$B$_{20}$/MgO multilayers by electrical transport and magnetometry measurements. These measurements suggest that an ultrathin magnetic oxide layer forms at the Co$_{20}$Fe$_{60}$B$_{20}$/MgO interface. At approximately 160 K, the oxide undergoes a phase transition from an insulating antiferromagnet at low temperatures to a conductive weak ferromagnet at high temperatures. This interfacial magnetic oxide is expected to have significant impact on the magnetic properties of CoFeB-based multilayers used in spin torque memories

Transarterial embolisation of a large focal nodular hyperplasia, using microspheres, in a paediatric patient

Benign liver tumours are uncommon in children, haemangiomas being the most frequent. Focal nodular hyperplasia (FNH) represents about 2% of paediatric liver tumours. In children, as in adults, a conservative approach is generally recommended. However, large lesions (greater than 5 cm) are more frequent in the paediatric age group, and in these cases, as well as in growing lesions, surgical removal may be advised. Transarterial embolisation (TAE) has been a successful alternative option described in older patients, especially in cases where surgical removal is not possible. This minimally invasive procedure may also become an option in the paediatric group. The authors report the case of a boy with a large FNH treated with TAE using microspheres

Transarterial embolisation of a large focal nodular hyperplasia, using microspheres, in a paediatric patient

Benign liver tumours are uncommon in children, haemangiomas being the most frequent. Focal nodular hyperplasia (FNH) represents about 2% of paediatric liver tumours. In children, as in adults, a conservative approach is generally recommended. However, large lesions (greater than 5 cm) are more frequent in the paediatric age group, and in these cases, as well as in growing lesions, surgical removal may be advised. Transarterial embolisation (TAE) has been a successful alternative option described in older patients, especially in cases where surgical removal is not possible. This minimally invasive procedure may also become an option in the paediatric group. The authors report the case of a boy with a large FNH treated with TAE using microspheres

Anaerobic decolorization of an azo dye by a mixed culture

Wool dyeing wastewater contains xenobiotic compounds that can be removed by biotechnological processes. Studies on various dyes showed that anaerobic processes are suitable to alter azo dyes as a first step of the biodegradation process. These compounds are reduced by anaerobic consortia to aromatic amines and its ultimate degradation can be achieved by a further aerobic treatment. Studies on degradation rate of an wool acid dye were performed in batch systems inoculated with anaerobic biomass. A commercial diazo dye, Acid Red 73, was added to the synthetic medium in which glucose was used as sole carbon source. Results indicated that the Acid Red 73 was partially degraded by a mixed culture of anaerobic bacteria and a decolorization of 90% was obtained. Kinetics studies on removal of the colour showed that the decolorization rate was several times faster than the degradation rate of glucose for a range of dye concentrations between 60 mg/L and 400 mg/L. A first order kinetic model was used for dye concentrations up to 200 mg/L. For higher concentrations a model similar to the Michaelis-Menten equation was better fitted to the experimental data.(undefined

Ovarian Ectopic Pregnancy in Adolescence

Ovarian pregnancy is one of the rarest types of extrauterine pregnancy. Its preoperative diagnosis remains a challenge since it presents quite similarly to tubal pregnancy and complicated ovarian cysts. Although in most cases, histology is necessary to confirm the diagnosis, we present an ovarian pregnancy in a teenager, correctly diagnosed during ultrasound examination