Performance comparison of differential space-time signalling schemes for OFDM systems

Differential transmit diversity is an attractive alternative to its coherent counterpart, especially for multiple antenna systems where channel estimation is more difficult to attain compared to that of single antenna systems. In this paper we compare two different types of differential transmit diversity techniques for OFDM based transmissions. The first technique uses differential space-time block codes (DSTBC) from orthogonal designs and the second uses the differential cyclic delay diversity (DCDD). The results compare the bit error performance for several transmit antenna configurations. The results show that DCDD offers a very close performance to that of DSTBC, with the advantage of a simplified receiver structure

The strength of beta-decays to the continuum

The beta-strength in beta-delayed particle decays has up to now been defined in a somewhat ad hoc manner that depends on the decay mechanism. A simple, consistent definition is presented that fulfils the beta strength sum rules. Special consideration is given to the modifications needed when employing R-matrix fits to data. As an example the 11Be(beta-p) decay is investigated through simple models.Comment: 18 pages, 4 figure

Cardiac transplantation with hearts from donors after circulatory declaration of death: haemodynamic and biochemical parameters at procurement predict recovery following cardioplegic storage in a rat model†

OBJECTIVES Donation after circulatory declaration of death (DCDD) could significantly improve the number of cardiac grafts for transplantation. Graft evaluation is particularly important in the setting of DCDD given that conditions of cardio-circulatory arrest and warm ischaemia differ, leading to variable tissue injury. The aim of this study was to identify, at the time of heart procurement, means to predict contractile recovery following cardioplegic storage and reperfusion using an isolated rat heart model. Identification of reliable approaches to evaluate cardiac grafts is key in the development of protocols for heart transplantation with DCDD. METHODS Hearts isolated from anaesthetized male Wistar rats (n = 34) were exposed to various perfusion protocols. To simulate DCDD conditions, rats were exsanguinated and maintained at 37°C for 15-25 min (warm ischaemia). Isolated hearts were perfused with modified Krebs-Henseleit buffer for 10 min (unloaded), arrested with cardioplegia, stored for 3 h at 4°C and then reperfused for 120 min (unloaded for 60 min, then loaded for 60 min). Left ventricular (LV) function was assessed using an intraventricular micro-tip pressure catheter. Statistical significance was determined using the non-parametric Spearman rho correlation analysis. RESULTS After 120 min of reperfusion, recovery of LV work measured as developed pressure (DP)-heart rate (HR) product ranged from 0 to 15 ± 6.1 mmHg beats min−1 10−3 following warm ischaemia of 15-25 min. Several haemodynamic parameters measured during early, unloaded perfusion at the time of heart procurement, including HR and the peak systolic pressure-HR product, correlated significantly with contractile recovery after cardioplegic storage and 120 min of reperfusion (P < 0.001). Coronary flow, oxygen consumption and lactate dehydrogenase release also correlated significantly with contractile recovery following cardioplegic storage and 120 min of reperfusion (P < 0.05). CONCLUSIONS Haemodynamic and biochemical parameters measured at the time of organ procurement could serve as predictive indicators of contractile recovery. We believe that evaluation of graft suitability is feasible prior to transplantation with DCDD, and may, consequently, increase donor heart availabilit

AKTIVITAS LIGNINOLISIS DARI BASIDIOMYCETES YANG DAPAT DIPAKAI UNTUK BIODEGRADASI DIOKSIN

Chemical compounds belonging to dioxin group are known to be highly toxic environmental pollutant. Polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran are produced during organic materials burning process. Pentachlorophenol, a compound similar to dioxin, is widely used as wood preservative, fungicide, bacteriocide, herbicide, algicide and insecticide. Some white-rot fungi have potential to produce lignin degrading enzyme and degrade dioxin compounds. The diversity of white-rot fungi in Indonesia provides potential source for environmental pollutant-degrading microorganisms. In this study, basidiomycetes were isolated from fruiting body and rotted wood samples which were collected from seven provinces in Indonesia. Three hundred seventy basidiomycete isolates were screened for dioxin degrading activity using dye-decolorization method. The result indicated that sixty isolates had dioxin degrading activity, three of which showed significant activity.Keywords: Ligninolytic, basidiomycetes, biodegradation, dioxin, fungus ABSTRAKSenyawa-senyawa kimia dalam kelompok dioksin telah diketahui sebagai polutan lingkungan yang sangat beracun. Dibenzo-p-dioksin terpoliklorinasi dan dibenzofuran terpoliklorinasi dihasilkan selama proses pembakaran bahan-bahan organik. Pentaklorofenol, suatu senyawa mirip dioksin, banyak digunakan sebagai pengawet kayu, fungisida, bakterisida, herbisida, algisida dan insektisida. Beberapa jamur pelapuk putih memiliki potensi untuk menghasilkan enzim pengurai lignin dan mendegradasi senyawa-senyawa dioksin. Keanekaragaman jamur pelapuk putih di Indonesia yang tinggi merupakan sumber potensial mikroorganisme pengurai polutan lingkungan. Pada kajian ini, basidiomisetes diisolasi dari sampel-sampel tubuh buah dan kayu lapuk yang diambil dari tujuh provinsi di Indonesia. Tiga ratus tujuh puluh isolat basidiomisetes telah diseleksi aktivitasnya sebagai pendegradasi dioksin. Metode dye-decolorization digunakan pada seleksi ini. Hasil seleksi menunjukkan bahwa enam puluh isolat basidiomisetes memiliki aktivitas sebagai pendegradasi dioksin, tiga isolat di antaranya menunjukkan aktivitas tertinggi.Kata kunci: Ligninolisis, basidiomisetes, biodegradasi, dioksin, jamurÂ

Djela koja ubijaju i djela koja ne ubijaju — filozofska analiza pravila mrtvog donora

In response to recent debates on the need to abandon the Dead Donor Rule (DDR) to facilitate vital-organ transplantation, I claim that, through a detailed philosophical analysis of the Uniform Determination of Death Act (UDDA) and the DDR, some acts that seem to violate DDR in fact do not, thus DDR can be upheld. The paper consists of two parts. First, standard apparatuses of the philosophy of language, such as sense, referent, truth condition, and definite description are employed to show that there exists an internally consistent and coherent interpretation of UDDA which resolves the Reduction Problem and the Ambiguity Problem that allegedly threaten the UDDA framework, and as a corollary, the practice of Donation after the Circulatory Determination of Death (DCDD) does not violate DDR. Second, an interpretation of the DDR, termed ‘No Hastening Death Rule’ (NHDR), is formulated so that, given that autonomy and non-maleficence principles are observed, the waiting time for organ procurement can be further shortened without DDR being violated.Kao odgovor na nedavne rasprave o potrebi napuštanja pravila mrtvog donora (DDR) radi olakšavanja transplantacije vitalnih organa, oslanjajući se na detaljnu filozofsku analizu Jedinstvenog zakona o utvrđivanju smrti (UDDA) i DDR-a, tvrdim da za neka djela za koja se čini da krše DDR, zapravo ga ne krše, stoga se DDR može podržati. Rad se sastoji od dva dijela. Prvo, koriste se standardni alati filozofije jezika, poput smisla, referencije, istinosnih uvjeta i određenog opisa kako bi se pokazalo da postoji interno konzistentna i koherentna interpretacija UDDA koja rješava problem redukcije i problem dvosmislenosti koji navodno prijete UDDA okviru, te kao posljedica toga, praksa darivanja nakon cirkulacijskog utvrđivanja smrti (DCDD) ne krši DDR. Drugo, tumačenje DDR-a, nazvano ‘Pravilo brze smrti’ (NHDR), formulirano je tako da se, s obzirom na poštivanje načela autonomije i ne-zlonamjernosti, vrijeme čekanja na nabavu organa može dodatno skratiti bez kršenja DDR-a

Triclosan Photolysis Facilitated by Polyethylene Microplastics; A Look into Surface Area

Plastic debris in natural water can absorb persistent organic pollutants (POPs) and catalyze their transformation to other molecules. This study aims to determine how the surface area of plastic affects the rate of POP photolysis. Photolysis reactions of triclosan and methyl triclosan are being carried out in the presence of polyethylene particles ranging from 5 to 925 um in diameter and sheet plastic with a surface area of at least 10mm, which displays the highest degree of photolysis. The results will provide insight into plastic surface interactions and energy sharing with adsorbed molecules