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Grooved tubes are widely used in electronic cooling modules. They are usuallt drawn, a term referring to molding. However, this process has limitations, especially in the production of smaller tubes. Therefore, this study examines the potential of an alternative process, dieless forming, in which the grooves on stainless steel are generated by pulsed laser-assisted air pressure. To begin with, the stainless steel tube in ambient air was heated using a pulsed laser. Then, groove samples were sliced for observation using an optical microscope (OM). Finally, the samples were analyzed using Scanning Electronic Microscope (SEM). The results demonstrate that grooves can be formed utilizing dieless forming with pulsed laser-assisted air pressure. The average observed depth of the grooves 208.5 um at 10-watt power and 0.01 Mpa gas pressure. In conclusion, grooves at a micro scale can be produced effectively by dieless forming for a range of industrial applications.

This brief presents a new fast algorithm along with its systolic array implementation for computing the N-point discrete cosine transform (DCT), where N is a power of two. The architecture requires [log.sub.2]N multipliers and can evaluate one complete N-point DCT (i.e., N transform samples) every N clock cycles. Due to the features of regularity and modularity, it is well suited to VLSI implementation. As compared to existing systolic DCT designs with the same throughput performance, the proposed one involves much less hardware complexity. Index Terms - Discrete cosine transform, fast algorithm, matrix-vector multiplication, systolic array, VLSI.

A new systolic array without matrix transposition hardware is proposed to compute the two-dimensional discrete cosine transform (2-D DCT) based on the row-column decomposition. This architecture uses [N.sup.2] multipliers to evaluate N X N-point DCT's at a rate of one complete transform per N dock cycles, where N is even. It possesses the features of regularity and modularity, and is thus well suited to VLSI implementation. As compared to existing pipelined regular architectures for the 2-D DCT, the proposed one has better throughput performance, smaller area-time complexity, and lower communication complexity. The new idea for the 2-D DCT is also extended to derive a similar systolic array for the 2-D inverse discrete cosine transform (IDCT). Simulation results demonstrate that the proposed 2-D DCT and IDCT architectures have good fixed-point error performance for both real image and random data. As a consequence, they are useful for applications where very high throughput rates are required.

Abstract Background The status of Toxoplasma gondii infection among primary schoolchildren (PSC) of the Democratic Republic of São Tomé and Príncipe (DRSTP), West Africa, remains unknown to date. Methods A serologic survey and risk factors associated T. gondii infection among PSC in the DRSTP was assessed by the latex agglutination (LA) test and a questionnaire interview including parents’ occupation, various uncomfortable symptoms, histories of eating raw or undercooked food, drinking unboiled water, and raising pets, was conducted in October 2010. Schoolchildren from 4 primary schools located in the capital areas were selected, in total 255 serum samples were obtained by venipuncture, of which 123 serum samples were obtained from boys (9.8 ± 1.4 yrs) and 132 serum samples were obtained from girls (9.7 ± 1.3 yrs). Results The overall seroprevalence of T. gondii infection was 63.1% (161/255). No significant gender difference in seroprevalence was found between boys (62.6%, 77/123) and girls (63.6%, 84/132) (p = 0.9). The older age group of 10 years had insignificantly higher seroprevalence (69.9%, 58/83) than that of the younger age group of 8 year olds (67.7%, 21/31) (p = 0.8). It was noteworthy that the majority of seropositive PSC (75.8%, 122/161) had high LA titers of ≥1: 1024, indirectly indicating acute or repeated Toxoplasma infection. Parents whose jobs were non-skilled workers (73.1%) showed significantly higher seroprevalence than that of semiskilled- (53.9%) or skilled workers (48.8%) (p p Children who claimed to have had recent ocular manifestation or headache, i.e. within 1 month, seemed to have insignificantly higher seroprevalence than those who did not (p > 0.05). Conclusions Parents’ educational level and cats kept indoors seemed to be the high risk factors for PSC in acquisition of T. gondii infection. While, ocular manifestation and/or headache of PSC should be checked for the possibility of being T. gondii elicited. Measures such as improving environmental hygiene and intensive educational intervention to both PSC and their parents should be performed immediately so as to reduce T. gondii infection of DRSTP inhabitants including PSC and adults.

A novel wide locking range divide-by-4 injection-locked frequency divider (ILFD) is proposed in the paper and was implemented in the TSMC 0.18 µm 1P6M CMOS process. The divide-by-4 ILFD uses two injection transistors in series and DC-biased above threshold voltage and a frequency doubler to enhance the function of linear mixers. At the drain-source bias of 0.9 V and at the incident power of 0 dBm, the locking range of the divide-by-4 is 2.6 GHz; from the incident frequency 12.2 to 14.8 GHz, the percentage is 19.26%. The core power consumption is 10.35 mW. The die area of ILFD is 1.026 × 0.943 mm2. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Two new VLSI architectures are proposed to compute the N-point discrete Fourier transform.

Nuclear migration through narrow constrictions is important for development, metastasis, and pro-inflammatory responses. Studies performed in tissue culture cells have implicated LINC (linker of nucleoskeleton and cytoskeleton) complexes, microtubule motors, the actin cytoskeleton, and nuclear envelope repair machinery as important mediators of nuclear movements through constricted spaces. However, little is understood about how these mechanisms operate to move nuclei in vivo . In C. elegans larvae, 6 pairs of hypodermal P cells migrate from lateral to ventral positions through a constricted space between the body wall muscles and the cuticle. P-cell nuclear migration is mediated in part by LINC complexes using a microtubule-based pathway and by an independent CDC-42/actin-based pathway. However, when both LINC complex and actin-based pathways are knocked out, many nuclei still migrate, suggesting the existence of additional pathways. Here we show that FLN-2 functions in a third pathway to mediate P-cell nuclear migration. The predicted N-terminal actin binding domain in FLN-2 that is found in canonical filamins is dispensable for FLN-2 function, this and structural predictions suggest that FLN-2 is not a divergent filamin. The immunoglobulin (Ig)-like repeats 4-8 of FLN-2 were necessary for P-cell nuclear migration. Furthermore, in the absence of the LINC complex component unc-84 , fln-2 mutants had an increase in P-cell nuclear rupture. We conclude that FLN-2 functions to maintain the integrity of the nuclear envelope in parallel with the LINC complex and CDC-42/actin-based pathways to move P-cell nuclei through constricted spaces.

Cellular migrations through constricted spaces are a crucial aspect of many developmental and disease processes including hematopoiesis, inflammation and metastasis. A limiting factor in these events is nuclear deformation. Here, we establish an in vivo model in which nuclei can be visualized while moving through constrictions and use it to elucidate mechanisms for nuclear migration. C. elegans hypodermal P-cell larval nuclei traverse a narrow space that is about 5% their width. This constriction is blocked by fibrous organelles, structures that pass through P cells to connect the muscles to cuticle. Fibrous organelles are removed just prior to nuclear migration, when nuclei and lamins undergo extreme morphological changes to squeeze through the space. Both actin and microtubule networks are organized to mediate nuclear migration. The LINC complex, consisting of the SUN protein UNC-84 and the KASH protein UNC-83, recruits dynein and kinesin-1 to the nuclear surface. Both motors function in P-cell nuclear migration, but dynein, functioning through UNC-83, plays a more central role as nuclei migrate towards minus ends of polarized microtubule networks. Thus, the nucleoskeleton and cytoskeleton are coordinated to move nuclei through constricted spaces., Competing Interests: The authors declare no competing or financial interests., (© 2016. Published by The Company of Biologists Ltd.)