Prospects and limitations of wakefield acceleration in solids

Advances in the generation of relativistic intensity pulses with wavelengths in the X-ray regime, through high harmonic generation from near-critical plasmas, opens up the possibility of X-ray driven wakefield acceleration. The similarity scaling laws for laser plasma interaction suggest that X-rays can drive wakefields in solid materials providing TeV/cm gradients, resulting in electron and photon beams of extremely short duration. However, the wavelength reduction enhances the quantum parameter $\chi$, hence opening the question of the role of non-scalable physics, e.g., the effects of radiation reaction. Using three dimensional Particle-In-Cell simulations incorporating QED effects, we show that for the wavelength $\lambda=5\,$nm and relativistic amplitudes $a_0=10$-100, similarity scaling holds to a high degree, combined with $\chi\sim 1$ operation already at moderate $a_0\sim 50$, leading to photon emissions with energies comparable to the electron energies. Contrasting to the generation of photons with high energies, the reduced frequency of photon emission at X-ray wavelengths (compared to at optical wavelengths) leads to a reduction of the amount of energy that is removed from the electron population through radiation reaction. Furthermore, as the emission frequency approaches the laser frequency, the importance of radiation reaction trapping as a depletion mechanism is reduced, compared to at optical wavelengths for $a_0$ leading to similar $\chi$.Comment: 9 pages, 7 figure

Orienting Graphs to Optimize Reachability

The paper focuses on two problems: (i) how to orient the edges of an undirected graph in order to maximize the number of ordered vertex pairs (x,y) such that there is a directed path from x to y, and (ii) how to orient the edges so as to minimize the number of such pairs. The paper describes a quadratic-time algorithm for the first problem, and a proof that the second problem is NP-hard to approximate within some constant 1+epsilon > 1. The latter proof also shows that the second problem is equivalent to ``comparability graph completion''; neither problem was previously known to be NP-hard

Hubungan Pola Perdarahan Uterus dengan Kadar Estradiol pada Akseptor Kontrasepsi Injeksi DMPA

Background: Bleeding disturbances are the main complaint that cause most DMPA users discontinuing contraceptive use. Mechanism underlying the bleeding disturbances is not clear. It is presumed that the condition is related to fluctuation of estradiol level or to low persistent estradiol level Objective: 1. To evaluate an association between bleeding pattern and estradiol level of DMPA users after 3, 6, 9, 12 months use. 2. To evaluate an association between estradiol level and length of use. 3. To evaluate an association between bleeding pattern and estradiol level, body mass index (BMI), age, parity, total cholesterol level of DMPA users.Design: Observational study, secondary analysis nested on “Randomized Controlled Trial Planibu® and Depo Progestin®”Material and Method:  Seventy DMPA users received injection every 3 months for 12 months. Before injection was administered, venous blood was taken and examination of estradiol level was done using Enzyme Imuno Absorbent Assay (ELISA). In addition, in-depth interview was also done on bleeding pattern for the last reference period (90 days). Subject was classified according to their bleeding pattern into groups of amenorrhea, oligomenorrhea, spotting, and bleeding,Results: All research subjects indicated low estradiol concentration with an average concentration less than 150 pg/ml. There was a correlation between length of usage and estradiol level; estradiol level after 12 months of usage was less than 100 pg/ml. There was no different between bleeding pattern and estradiol in month 3, 6, 9,12  using bivariate analysis with t-test with amenorrhea group as reference and p > 0,05. T-test and Chi Square analyses using amenorrhea group as reference stated that there was no association between bleeding pattern and age, BMI, and parity. Using multivariate analysis with Multinomial Logistic Regression, it was stated that correlation between estradiol concentration and bleeding  pattern was not affected by age, body mass index, or total cholesterol level. There was an association between bleeding pattern and cholesterol level using bivariate and multivariate analyses.Conclusion:  1. Estradiol level in various bleeding pattern after 3,6,9,12 month of usage was not different. 2. There was correlation between low estradiol level and length of usage. 3. Association between bleeding pattern and estradiol level was not influenced by age, parity and body mass index, and total cholesterol level.Keywords: bleeding pattern, estradiol, DMPA, injectable contraceptio

Hubungan Pola Perdarahan Uterus dengan Kadar Estradiol pada Akseptor Kontrasepsi Injeksi DMPA

Background: Bleeding disturbances are the main complaint that cause most DMPA users discontinuing contraceptive use. Mechanism underlying the bleeding disturbances is not clear. It is presumed that the condition is related to fluctuation of estradiol level or to low persistent estradiol level Objective: 1. To evaluate an association between bleeding pattern and estradiol level of DMPA users after 3, 6, 9, 12 months use. 2. To evaluate an association between estradiol level and length of use. 3. To evaluate an association between bleeding pattern and estradiol level, body mass index (BMI), age, parity, total cholesterol level of DMPA users.Design: Observational study, secondary analysis nested on “Randomized Controlled Trial Planibu® and Depo Progestin®”Material and Method: Seventy DMPA users received injection every 3 months for 12 months. Before injection was administered, venous blood was taken and examination of estradiol level was done using Enzyme Imuno Absorbent Assay (ELISA). In addition, in-depth interview was also done on bleeding pattern for the last reference period (90 days). Subject was classified according to their bleeding pattern into groups of amenorrhea, oligomenorrhea, spotting, and bleeding,Results: All research subjects indicated low estradiol concentration with an average concentration less than 150 pg/ml. There was a correlation between length of USAge and estradiol level; estradiol level after 12 months of USAge was less than 100 pg/ml. There was no different between bleeding pattern and estradiol in month 3, 6, 9,12 using bivariate analysis with t-test with amenorrhea group as reference and p > 0,05. T-test and Chi Square analyses using amenorrhea group as reference stated that there was no association between bleeding pattern and age, BMI, and parity. Using multivariate analysis with Multinomial Logistic Regression, it was stated that correlation between estradiol concentration and bleeding pattern was not affected by age, body mass index, or total cholesterol level. There was an association between bleeding pattern and cholesterol level using bivariate and multivariate analyses.Conclusion: 1. Estradiol level in various bleeding pattern after 3,6,9,12 month of USAge was not different. 2. There was correlation between low estradiol level and length of USAge. 3. Association between bleeding pattern and estradiol level was not influenced by age, parity and body mass index, and total cholesterol level

Pollen and seed morphology of rhinacanthus nees and hypoestes Sol. ex R. Br. (Acanthaceae) of Yemen

Pollens and seeds of Hypoestes and Rhinacanthus collected from different field localities in Taiz and Soqotra Island, Yemen were investigated by using light and scanning electron microscopes. Pollen grains of Hypoestes were prolate in equatorial view, lobate trigonal to lobate circular in polar view whereas those of Rhinacanthus were subspheroidal and rounded trigonal in polar view. The aperture was tricolporate and exine ornamentation was coarsely reticulate for all species in the two genera. Scanning electron microscopy and morphological observations showed that mature dry seeds of Hypoestes and Rhinacanthus have various sizes and shapes, the surface ornamentations observed were reticulate to cristate, an addition to the tuberculum and papillae. The three Hypoestes species differ in the seed structure which are useful for identification and their high structural diversity provides an important taxonomic value for species differentiation

Enhancing AmBC Systems with Deep Learning for Joint Channel Estimation and Signal Detection

The era of ubiquitous, affordable wireless connectivity has opened doors to countless practical applications. In this context, ambient backscatter communication (AmBC) stands out, utilizing passive tags to establish connections with readers by harnessing reflected ambient radio frequency (RF) signals. However, conventional data detectors face limitations due to their inadequate knowledge of channel and RF-source parameters. To address this challenge, we propose an innovative approach using a deep neural network (DNN) for channel state estimation (CSI) and signal detection within AmBC systems. Unlike traditional methods that separate CSI estimation and data detection, our approach leverages a DNN to implicitly estimate CSI and simultaneously detect data. The DNN model, trained offline using simulated data derived from channel statistics, excels in online data recovery, ensuring robust performance in practical scenarios. Comprehensive evaluations validate the superiority of our proposed DNN method over traditional detectors, particularly in terms of bit error rate (BER). In high signal-to-noise ratio (SNR) conditions, our method exhibits an impressive approximately 20% improvement in BER performance compared to the maximum likelihood (ML) approach. These results underscore the effectiveness of our developed approach for AmBC channel estimation and signal detection. In summary, our method outperforms traditional detectors, bolstering the reliability and efficiency of AmBC systems, even in challenging channel conditions.Comment: Accepted for publication in the IEEE Transactions on Communication

Prognostic factors at birth for stunting at 24 months of age in rural Indonesia

Background The problems of stunting are its high prevalence as well as the complexity of its risk factors. Identifying the modifiable prognostic factors at birth may reduce the shortterm as well as longterm effects of stunting in later life. Objective To estimate the influence of prognostic factors detected at birth for stunting at 24 months of age and the occurence of reversal of stunting at 24 months of age among children in a rural area of Indonesia. Methods Subjects (n=343) were born to mothers participating in a randomized controlled, double-blind, community-based study of vitamin A and/or zinc supplementation during pregnancy and followed from June 1998 to October 2000. The children were followed prospectively from birth until 2 years of age with monthly measurements of length from birth to 12 months, and again at 18 and 24 months. Data on potential prognostic factors detected at birth, i.e., maternal, child, and household facilities, were collected by trained field workers at home visits. The incidence and risk ratio were calculated to assess the influence of the possible prognostic factors detected at birth on stunting at 24 months of age among these children. Results Boys who were born prematurely had significantly higher risk of stunting at 24 months of age compared to girls born maturely. The incidences of stunting at 24 months of age according to gender, and gestational age were 33.9% boys vs. 22.5% girls (RR 1.80; 95%CI 1.06 to 3.09), and 33.3% premature vs. 27.6% mature (RR 7.11; 95%CI 2.07 to 24.48), respectively. Conclusion Boys who were born prematurely have significantly higher risk to become stunted at 24 months of age. The occurrence of reversal of stunting at 24 months of age is low

The embryonic development and formation of Bunnei (Barbus sharpeyi Gunther, 1874)

Understanding the embryogenesis of Bunni is a useful tool for finding the time and suitable environmental conditions for spawning, growth requirements and use of techniques to increase the growth rate and survival. The stages of embryonic development for Bunnei (Barbus sharpeyi) was investigated in 22°C. The reared brood stocks were spawned in captivity condition. The oocytes were spherical, brown and very adhesive. The cleavage was fast and the first division was recorded within 15-20 minutes after fertilization. The blastulation and gastrulation were investigated in 7:40 and 13:10 hours after fertilization with the yolk sac diameter of 1.18±0.061mm (Mean±SD), respectively. The organogenesis was started 21 hours after the fertilization, when the blastopore was closed and notochord was formed. The embryonic stages were continued by appearance the brain, the somites and the melanophores on the yolk sac. The heart was beaten and shown the blood circulation 65 hours after the fertilization. The head, tail and pectoral fins were moved frequently. The embryo reached to pre hatching and final hatching 79:10 and 84:10 hours after fertilization, respectively, and the embryo existed from corion with the length of about 5.29±0/121mm (Mean±SD)

Aktivitas Fisik dan Konsumsi Camilan pada Remaja Obesitas

Tujuan: Penelitian ini untuk mengetahui adanya perbedaan aktivitas fisik dan konsumsi camilan pada remaja obesitas di desa dan kota di Bantul.Metode: Penelitian ini menggunakan rancangan penelitian case control, dengan populasi remaja sekolah menengah atas (SMA) negeri di Kabupaten Bantul. Kasus adalah remaja yang didiagnosis obesitas pada tahap skrining, sedangkan kontrol adalah remaja dengan berat badan normal. Analisis data meliputi univariabel yang menyajikan distribusi frekuensi, bivariabel dengan uji chi-square dan uji-t dan mulitivariabel dengan uji regresi logistik.Hasil: Remaja dengan aktivitas fisik ringan memiliki peluang hampir 5 kali lebih besar mengalami obesitas dibandingkan remaja dengan aktivitas fisik sedang (OR 4,96 (CI 95%:2.14 -11.63). Hubungan antara jenis camilan dan obesitas juga memiliki hubungan yang bermakna secara statistik dan praktis, yaitu obesitas banyak di temukan sebanyak 2 kali lebih besar pada remaja dengan konsumsi camilan goreng dibandingkan dengan remaja yang mengkonsumsi camilan non goreng.Kesimpulan: Terdapat perbedaan rerata berat dan asupan camilan pada remaja obesitas dan non obesitas. Aktivitas fisik ringan, frekuensi camilan tinggi, jenis camilan gorengan, berat camilan dan asupan camilan tinggi berpeluang lebih besar meningkatkan obesitas remaja