Wave-like Solutions for Bianchi type-I cosmologies in 5D

We derive exact solutions to the vacuum Einstein field equations in 5D, under the assumption that (i) the line element in 5D possesses self-similar symmetry, in the classical understanding of Sedov, Taub and Zeldovich, and that (ii) the metric tensor is diagonal and independent of the coordinates for ordinary 3D space. These assumptions lead to three different types of self-similarity in 5D: homothetic, conformal and "wave-like". In this work we present the most general wave-like solutions to the 5D field equations. Using the standard technique based on Campbell's theorem, they generate a large number of anisotropic cosmological models of Bianchi type-I, which can be applied to our universe after the big-bang, when anisotropies could have played an important role. We present a complete review of all possible cases of self-similar anisotropic cosmologies in 5D. Our analysis extends a number of previous studies on wave-like solutions in 5D with spatial spherical symmetry

Cell division in apicomplexan parasites is organized by a homolog of the striated rootlet fiber of algal flagella

Apicomplexa are intracellular parasites that cause important human diseases including malaria and toxoplasmosis. During host cell infection new parasites are formed through a budding process that parcels out nuclei and organelles into multiple daughters. Budding is remarkably flexible in output and can produce two to thousands of progeny cells. How genomes and daughters are counted and coordinated is unknown. Apicomplexa evolved from single celled flagellated algae, but with the exception of the gametes, lack flagella. Here we demonstrate that a structure that in the algal ancestor served as the rootlet of the flagellar basal bodies is required for parasite cell division. Parasite striated fiber assemblins (SFA) polymerize into a dynamic fiber that emerges from the centrosomes immediately after their duplication. The fiber grows in a polarized fashion and daughter cells form at its distal tip. As the daughter cell is further elaborated it remains physically tethered at its apical end, the conoid and polar ring. Genetic experiments in Toxoplasma gondii demonstrate two essential components of the fiber, TgSFA2 and 3. In the absence of either of these proteins cytokinesis is blocked at its earliest point, the initiation of the daughter microtubule organizing center (MTOC). Mitosis remains unimpeded and mutant cells accumulate numerous nuclei but fail to form daughter cells. The SFA fiber provides a robust spatial and temporal organizer of parasite cell division, a process that appears hard-wired to the centrosome by multiple tethers. Our findings have broader evolutionary implications. We propose that Apicomplexa abandoned flagella for most stages yet retained the organizing principle of the flagellar MTOC. Instead of ensuring appropriate numbers of flagella, the system now positions the apical invasion complexes. This suggests that elements of the invasion apparatus may be derived from flagella or flagellum associated structures

Colon cancer in a 12-year-old girl with hypertriglyceridemia

Colorectal cancer is usually considered a disease of the elderly; however, in a small fraction of patients (2%-3% of all affected individuals), colorectal malignancies may develop earlier. The reasons whereby some individuals develop colorectal cancer at a young age are poorly understood. In a 12-year-old girl, a malignancy was diagnosed in the ascending colon. There was no familial history of Lynch syndrome or familial adenomatous polyposis. The metabolic profile of the patient revealed hypertriglyceridemia and low high-density lipoprotein cholesterol levels at nine years, then diagnosed as familial hypertriglyceridemia due to a constitutional mutation in the APOA5 gene (c.427delC). Moreover, variants possibly increasing the risk of cancer were detected in MSH6 (c.3438+11_3438+14delCTTA, intron 5) and APC (I1307K). The patient showed a rather unusual dietary pattern, since her basic alimentation from weaning consisted almost exclusively of meat homogenates and, subsequently, roasted meat or cutlets. Other foods, including fish, vegetables, sweets, and pasta, were refused. In this case, genetic and environmental factors could have acted in a particularly accelerated manner. Indeed, the genetic background of the patient (familial hypertriglyceridemia and polymorphisms predisposing to colorectal cancer) may have favored a dietary-driven colorectal carcinogenesis, resulting in an extremely early onset development of malignancy

Home Parenteral Nutrition: A Hospital‐Based Program with Commercial Logistic Support

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141442/1/jpen0585.pd

Correlation Between Body Weight Day Old Chick (DOC) and Body Weight Each Week from Commercial Farms in Province of Rizal, Philippines

Farmers of the poultry industry are seeking new and more efficient techniques to produce broilers more quickly, without sacrificing quality, nutrition, or cost, as the demand for poultry rises in conjunction with the human population. This study analyzed the weight of broilers from day 1 to harvest day to determine the impact of each daily or weekly weight on the final weight of the broilers. The experiment was conducted in a conventional type of housing. One hundred thousand male Cobb strain day-old chicks were housed. The feed of the chicks consisted of commercially blended feeds including CP and BMEG, as well as vitamins, minerals, and amino acids, in accordance with nutritional needs. The study examined the relationship between the day-old chick’s weight and the flock’s weekly weight and discovered that there is no correlation between the day-old chick’s weight and its weekly weight at days 7, 14, 21, 28, and 35 (harvest weight). However, the weight at the 7-day mark had the greatest effect on the potential market weight of the broiler. It can be determined that the early life of chickens plays a crucial role in their productivity

Active gravitational mass and the invariant characterization of Reissner-Nordstrom spacetime

We analyse the concept of active gravitational mass for Reissner-Nordstrom spacetime in terms of scalar polynomial invariants and the Karlhede classification. We show that while the Kretschmann scalar does not produce the expected expression for the active gravitational mass, both scalar polynomial invariants formed from the Weyl tensor, and the Cartan scalars, do.Comment: 6 pages Latex, to appear in General Relativity and Gravitatio

Effective spacetime from multi-dimensional gravity

We study the effective spacetimes in lower dimensions that can be extracted from a multidimensional generalization of the Schwarzschild-Tangherlini spacetimes derived by Fadeev, Ivashchuk and Melnikov ({\it Phys. Lett,} {\bf A 161} (1991) 98). The higher-dimensional spacetime has $D = (4 + n + m)$ dimensions, where $n$ and $m$ are the number of "internal" and "external" extra dimensions, respectively. We analyze the effective $(4 + n)$ spacetime obtained after dimensional reduction of the $m$ external dimensions. We find that when the $m$ extra dimensions are compact (i) the physics in lower dimensions is independent of $m$ and the character of the singularities in higher dimensions, and (ii) the total gravitational mass $M$ of the effective matter distribution is less than the Schwarzshild mass. In contrast, when the $m$ extra dimensions are large this is not so; the physics in $(4 + n)$ does explicitly depend on $m$, as well as on the nature of the singularities in high dimensions, and the mass of the effective matter distribution (with the exception of wormhole-like distributions) is bigger than the Schwarzshild mass. These results may be relevant to observations for an experimental/observational test of the theory.Comment: A typo in Eq. (24) is fixe

The Zakharov-Shabat spectral problem on the semi-line: Hilbert formulation and applications

The inverse spectral transform for the Zakharov-Shabat equation on the semi-line is reconsidered as a Hilbert problem. The boundary data induce an essential singularity at large k to one of the basic solutions. Then solving the inverse problem means solving a Hilbert problem with particular prescribed behavior. It is demonstrated that the direct and inverse problems are solved in a consistent way as soon as the spectral transform vanishes with 1/k at infinity in the whole upper half plane (where it may possess single poles) and is continuous and bounded on the real k-axis. The method is applied to stimulated Raman scattering and sine-Gordon (light cone) for which it is demonstrated that time evolution conserves the properties of the spectral transform.Comment: LaTex file, 1 figure, submitted to J. Phys.