Yolcu Taşıma Maliyetlerinin Faaliyet Tabanlı Maliyetleme Yöntemine Göre Hesaplanması: Devlet Demiryolları İşletmesinde Vaka Çalışması

Amaç – 1985 yılında Dr. Robin Cooper tarafından geliştirilen faaliyet tabanlı maliyetleme yöntemi;mamul ya da hizmet üretimi sırasında tüketilen kaynak ve faaliyetlerin maliyetlerini belirleyerekmamul ya da hizmet maliyetlerinin doğru bir şekilde hesaplanmasını sağlamaktadır. İşletmelerinperformans ölçümlerini arttırabilmek amacıyla maliyetlerin iyileştirilmesini sağlayan yöntem,işletme yöneticilerinin karar vermelerine de yardımcı olmaktadır. İnsanların ve üretilen mamul veyahizmetlerin yer değiştirmesini sağlayan ulaştırma sektöründe de alınacak kararlar ve bu kararlardoğrultusunda oluşacak maliyetler önem taşımaktadır. Çalışmada ulaştırma sektöründe yer alanTCDD İşletmesi’nde yolculara sunulan hizmet maliyetlerinin hesaplanmasında faaliyet tabanlımaliyetleme yöntemi incelenmiş ve vaka çalışması yöntemi kullanılarak, bu sektörde ulaştırmamaliyetlerinin faaliyet tabanlı maliyetleme yöntemine göre tasarımı gösterilmiştir.Yöntem – Ulaştırma sektöründeki özel durumların sistematik bir şekilde araştırmasınınyapılabilmesi için çalışmada örnek vaka yöntemi kullanılmıştır.Bulgular – Çalışmada; işletmenin geleneksel maliyetleme yöntemine göre hesaplanan koltuk başı veyolcu Km birim maliyetlerinin, faaliyet tabanlı maliyetleme yöntemine göre hesaplanan koltuk başıve yolcu Km birim maliyetlerinden daha fazla olduğu tespit edilmiştir.Tartışma – Ulaştırma sektöründe hizmet sunumuna başlamadan önce faaliyet tabanlı maliyetlemeyöntemi analizi yapılmadığı durumlarda işletmelerin daha fazla taşıma maliyetlerine katlanmasıdurumu söz konusu olabilmektedir. Bu nedenle, işletmelerin bu analizleri yaparak ilgili kararlarıvermesi işletmeler açısından önem taşımaktadır

Reanalysis of human blastocysts with different molecular genetic screening platforms reveals significant discordance in ploidy status

The objective of this study is to determine mosaicism and its effect on blastocysts; abnormal blastocysts determined by molecular testing were sequentially biopsied and retested. We re-biopsied 37 blastocyst-stage abnormal embryos from eight patients, which were reanalyzed to determine the level of concordance between biopsies and inter-laboratory congruence between reputable commercial PGS laboratories. The main outcome measures were intra-embryo variation between sequential embryo biopsies and inter-laboratory variation between two PGS laboratories. The compatibility between both aCGH and NGS was found to be 11 % (3/27). Importantly, 9/27 (33 %) of embryos originally reported to be aneuploid, upon repeat assessment, were found to be euploid. The concurrence for SNP array and NGS was 50 % (3/6), and 17 % (1/6) of these abnormal embryos tested normal upon re-evaluation with NGS. NGS resulted 41 % (11/27) normal results when 27 of CGH abnormal embryos were retested. Concordance between aCGH and NGS was 4 % (1/27) whereas in three instances, gender discrepancy was observed with NGS when aCGH abnormal embryos were reanalyzed. The results of these studies reinforce the prevalence of inconsistencies during PGS evaluation of trophectoderm biopsies possibly due to variations in platform sensitivity and heightening concerns over the clinical tractability of such technology in human ARTs.

Parthenogenetic activation of bovine oocytes using bovine and murine phospholipase C zeta

Background - During natural fertilization, sperm fusion with the oocyte induces long lasting intracellular calcium oscillations which in turn are responsible for oocyte activation. PLCZ1 has been identified as the factor that the sperm delivers into the egg to induce such a response. We tested the hypothesis that PLCZ1 cRNA injection can be used to activate bovine oocytes. Results - Mouse and bovine PLCZ1 cRNAs were injected into matured bovine oocytes at different concentrations. Within the concentrations tested, mouse PLCZ1 injection activated bovine oocytes at a maximum rate when the pipette concentration of cRNA ranged from 0.25 to 1 μg/μL, while bovine PLCZ1 was optimal at 0.1 μg/μL. At their most effective concentrations, PLCZ1 induced parthenogenetic development at rates similar to those observed using other activation stimuli such as Ionomycin/CHX and Ionomycin/DMAP. Injection of mouse and bovine PLCZ1 cRNA induced dose-dependent sperm-like calcium oscillations whose frequency increased over time. Injection of bovine and mouse PLCZ1 cRNA also induced IP3R-1 degradation, although bovine PLCZ1 cRNA evoked greater receptor degradation than its mouse counterpart. Conclusion - Injection of PLCZ1 cRNA efficiently activated bovine oocytes by inducing a sperm-like calcium oscillatory pattern. Importantly, the high rate of aneuploidy encountered in parthenogenetic embryos activated by certain chemical means was not observed in PLCZ1 activated embryos

Telomere Dynamics in Human Cells Reprogrammed to Pluripotency

BACKGROUND:Human induced pluripotent stem cells (IPSCs) have enormous potential in the development of cellular models of human disease and represent a potential source of autologous cells and tissues for therapeutic use. A question remains as to the biological age of IPSCs, in particular when isolated from older subjects. Studies of cloned animals indicate that somatic cells reprogrammed to pluripotency variably display telomere elongation, a common indicator of cell "rejuvenation." METHODOLOGY/PRINCIPAL FINDINGS:We examined telomere lengths in human skin fibroblasts isolated from younger and older subjects, fibroblasts converted to IPSCs, and IPSCs redifferentiated through teratoma formation and explant culture. In IPSCs analyzed at passage five (P5), telomeres were significantly elongated in 6/7 lines by >40% and approximated telomere lengths in human embryonic stem cells (hESCs). In cell lines derived from three IPSC-teratoma explants cultured to P5, two displayed telomeres shortened to lengths similar to input fibroblasts while the third line retained elongated telomeres. CONCLUSIONS/SIGNIFICANCE:While these results reveal some heterogeneity in the reprogramming process with respect to telomere length, human somatic cells reprogrammed to pluripotency generally displayed elongated telomeres that suggest that they will not age prematurely when isolated from subjects of essentially any age

Disciplina radnje, evokacija s fusnotama uloga vlaka, u školovanju

Tion. b) Pipette advanced into the oocyte; cytoplasm is aspirated to break the plasma membrane. c) Aspirated cytoplasm and Texas Red dextran are injected into the oocyte. d) Schematic representation of the microscope reticulum used as guide to control the injected volume. The oocyte is represented in yellow and the pipette in blue. The red lines indicate the volume introduced into the oocyte which, calculated measuring the pipette internal diameters at both ends, is 5.9 pL. e) An oil drop of the same size as the injected volume is shown next to an oocyte. f) Oocytes injected using Texas Red dextran. g) From left to right, oocyte injected 2X and 1X the normal volume of Texas Red dextran. h) Fluorescent intensity profile of the line shown in f. i) Fluorescent intensity profile of the line shown in g. j) Developmental rates of injected and uninjected bovine oocytes after activation using ionomycin/DMAP.<p><b>Copyright information:</b></p><p>Taken from "Parthenogenetic activation of bovine oocytes using bovine and murine phospholipase C zeta"</p><p>http://www.biomedcentral.com/1471-213X/8/16</p><p>BMC Developmental Biology 2008;8():16-16.</p><p>Published online 19 Feb 2008</p><p>PMCID:PMC2266721.</p><p></p