Całkowita histerektomia laparoskopowa metodą pojedynczego nacięcia pępkowego: technika i pierwsze doświadczenia w Turcji

Objectives: The aim of the study is to determine the results of our initial experience of 32 cases who underwent single incision total laparoscopic hysterectomy. Materials and Methods: Thirty-two patients who underwent transumbilical single incision total laparoscopic hysterectomy between March 2009 and February 2011 were reviewed retrospectively at the Department of Obstetrics and Gynecology, Ege University Faculty of Medicine, Izmir, Turkey. Articulating and rigid instruments, 30 degrees 10 mm telescope, SILS™ port and advanced bipolar and mechanical energy modalities were used during the procedure. Duration of surgery, length of hospital stay, mean blood loss and postoperative complications were assessed. Results: Mean age of patients and mean operation time were 48 years (ranged 42-55) and 108 minutes (ranged 80-180), respectively. In all cases vaginal cuff s were closed with either intracorporeal or extracorporeal separate sutures. There were no intraoperative complications. All patients were discharged within 48 hours postoperatively. The mean length of hospital stay and mean blood loss were as 1.6 days (range 1-2) and 45 ml (range 30-100), respectively. Conclusions: Total laparoscopic hysterectomy performed through transumbilical single incision is technically feasible and safe. Development of advanced fl exible instrumentation and visualization platform may facilitate this new operative approach.Cel pracy: Celem tego badania była ocena wyników naszego pierwszego doświadczenia z 32 pacjentkami, które przeszły całkowitą laparoskopową histerektomię metodą pojedynczego nacięcia. Materiał i metoda: Przeanalizowano retrospektywnie trzydzieści dwie pacjentki, które przeszły całkowitą laparoskopową histerektomię metodą pojedynczego nacięcia pępkowego pomiędzy marcem 2009 a lutym 2011, w Oddziale Położniczo-Ginekologicznym, Ege University Faculty of Medicine w Turcji. W trakcie procedury użyto instrumentarium giętkiego i sztywnego, endoskopu o kącie widzenie 30°, 10mm, portu SILSTM i zaawansowanych urządzeń bipolarnych oraz energii mechanicznej. Oceniono czas trwania operacji, długość pobytu w szpitalu, średnią utratę krwi i komplikacje pooperacyjne. Wyniki: Średnia wieku pacjentek wynosiła 48 lat (zakres 42-55), średni czas trwania operacji 108 minut (zakres 80-180). We wszystkich przypadkach mankiet pochwy zeszyto osobnymi szwami wewnątrzbrzusznymi lub zewnątrzbrzusznymi. Nie obserwowano żadnych powikłań w trakcie operacji. Wszystkie pacjentki wypisano do domu w ciągu 48 godzin od operacji. Średni czas pobytu w szpitalu wynosił 1,6 dni (zakres 1-2) a utrata krwi wynosiła 45ml (zakres 30-100). Wnioski: Całkowita laparoskopowa histerektomia metodą pojedynczego nacięcia pępkowego jest technicznie wykonalna i bezpieczna. Ulepszanie zaawansowanego, elastycznego instrumentarium oraz możliwości wizualizacji ułatwiają to nowe podejście operacyjne

Prevalence of tick-borne haemoparasites in small ruminants in Turkey and diagnostic sensitivity of single-PCR and RLB

Background: Tick-borne haemoparasitic diseases (TBHDs), caused by Theileria, Babesia, Anaplasma and Ehrlichia, are common in regions of the world where the distributions of host, pathogen and vector overlap. Many of these diseases threaten livestock production and some also represent a concern to human public health. The primary aim of this study was to determine the prevalence of the above-mentioned pathogens in a large number of blood samples (n = 1979) collected from sheep (n = 1727) and goats (n = 252) in Turkey. A secondary aim was to assess the diagnostic sensitivity of a number of species-specific polymerase chain reaction (PCR) tests and the reverse line blotting (RLB) assay. DNA samples were screened using species-specific PCR for the presence of Theileria ovis, Theileria sp. MK, T. lestoquardi, T. uilenbergi, T. luwenshuni, Babesia ovis, Anaplasma ovis and A. phagocytophilum while RLB was undertaken to test for the presence of all known Theileria, Babesia, Anaplasma and Ehrlichia species. The diagnostic sensitivity of these two approaches was then compared in terms of their ability to detect single species and mixed infections. Results: Overall, 84 and 74.43% of the small ruminants sampled were identified as hosting one or more pathogen(s) by species-specific PCR and RLB respectively. The presence of Theileria sp. OT1, T. luwenshuni and T. uilenbergi in Turkey was revealed for the first time while the presence of Babesia motasi, B. crassa and T. separata in Turkish small ruminants was confirmed using molecular methods. A high prevalence of mixed infection was evident, with PCR and RLB approaches indicating that 52.24 and 35.42% of animals were co-infected with multiple species, respectively. More than 80% of the mixed infections contained T. ovis and/or A. ovis. The RLB approach was found to be capable of detecting mixed infections with species such as Theileria sp. OT1, Theileria sp. OT3, T. separata, B. crassa and Babesia spp. Conclusion: The results indicated that pathogens causing TBHDs are highly prevalent in sheep and goats in Turkey. The diagnostic sensitivity of species-specific single PCR was generally higher than that of RLB. However, the latter approach was still capable of identifying a high proportion of individuals containing mixed-species infections. The use of species-specific single PCR is recommended to accurately estimate pathogen prevalence and to identify co-infected hosts

GCN-FFNN: A two-stream deep model for learning solution to partial differential equations

This paper introduces a novel two-stream deep model based on graph convolutional network (GCN) architecture and feed-forward neural networks (FFNN) for learning the solution of nonlinear partial differential equations (PDEs). The model aims at incorporating both graph and grid input representations using two streams corresponding to GCN and FFNN models, respectively. Each stream layer receives and processes its input representation. As opposed to FFNN which receives a grid-like structure, the GCN stream layer operates on graph input data where the neighborhood information is incorporated through the adjacency matrix of the graph. In this way, the proposed GCN-FFNN model learns from two types of input representations, i.e. grid and graph data, obtained via the discretization of the PDE domain. The GCN-FFNN model is trained in two phases. In the first phase, the model parameters of each stream are trained separately. Both streams employ the same error function to adjust their parameters by enforcing the models to satisfy the given PDE as well as its initial and boundary conditions on grid or graph collocation (training) data. In the second phase, the learned parameters of two-stream layers are frozen and their learned representation solutions are fed to fully connected layers whose parameters are learned using the previously used error function. The learned GCN-FFNN model is tested on test data located both inside and outside the PDE domain. The obtained numerical results demonstrate the applicability and efficiency of the proposed GCN-FFNN model over individual GCN and FFNN models on 1D-Burgers, 1D-Schrödinger, 2D-Burgers, and 2D-Schrödinger equations

Prognostic importance of Mean Platelet Volume/ Platelet Ratio Before Treatment in Patients with Metastatic Pancreatic Cancer

Objectives: Pancreatic cancer (PC) is one of the cancers with the worst prognosis in the world. Despite protooncogenes such as BRCA and PALB2 , effective, inexpensive, and simple methods for predicting the prognosis of patients with metastatic PC are still lacking. We aim to investigate whether mean platelet volume/ platelet (MPV/PLT) and platelet indices such as MPV and plateletcrit (PCT) have a prognostic significance in patients with metastatic PC. Methods: Patients diagnosed with metastatic PC in 3 centers in Turkey between 2016 and 2022 were analyzed retrospectively. We recorded patient’s demographic data such as age, gender, performance status and platelet, MPV and PCT. Overall survival (OS) and progression-free survival (PFS) were also recorded. There were 80 patients in our study. Results: Median PFS was found 6.2 months for MPV/PLT ratio 0.045 group retrospectively. The median PFS of the MPV/PLT ratio ≤0.045 groupwas shorter than MPV/PLT ratio >0.045 group, but there wasn’t statistically meaningful difference between the groups (p:0,957). Median OS for the MPV/PLT ratio ≤0.045 groupwas 10.1 months and the MPV/PLT ratio for the >0.045 group was 9 months, but there wasn’t statistically significant difference between the groups (p:0.506).There was nosurvival difference between the groups when comparing both MPV and PCT status. Conclusion: MPV/PLT ratio is a cheap, simple and useful marker and can be used in our daily practice to predict the prognosis of patients with advanced PC, if confirmed by prospective studies and larger patient numbers

Vitamin D status among adults in the Aegean region of Turkey

<p>Abstract</p> <p>Background</p> <p>Vitamin D is a lipid-soluble hormone found in certain foods and synthesized from precursors in the skin when exposed to ultraviolet light. Vitamin D plays a critical role in bone metabolism and many cellular and immunological processes and low levels have been associated with several chronic and infectious diseases. Vitamin D status is assessed by measuring the concentration of serum 25-hydroxyvitamin D [25(OH)D]. Vitamin D deficiency is reported to be common worldwide, but little has been reported about the vitamin D status of adults in Turkey. In this cross-sectional study, we determined the prevalence of 25(OH)D deficiency in adults residing in a city in the Aegean region of Turkey.</p> <p>Methods</p> <p>A survey was conducted on a representative sample of adults over 20 years old in a non-coastal city at the end of the winter season. Of the 209 households selected by random sampling, 8.6% (n = 18) were unoccupied and 21.5% (n = 45) refused to participate. Blood samples were taken and questions about medical history, vitamin supplementation, sunlight exposure, and dietary calcium and vitamin D intake were asked in face-to-face interviews of 391 adults living in the remaining households.</p> <p>Results</p> <p>The mean serum 25(OH)D concentration was 16.9±13.09 ng/mL, with 74.9% of the subjects having 25(OH)D deficiency (<20 ng/mL), 13.8% having insufficiency (20-29.99 ng/mL), and 11.3% of the subjects having sufficient 25(OH)D (≥30 ng/mL) levels. 25(OH)D deficiency was more common among females (78.7%) than males (66.4%, p < 0.05).</p> <p>Conclusion</p> <p>Adults living in an urban, non-coastal setting in Turkey have a high prevalence of vitamin D deficiency.</p

THE EFFICACY OF DICLOFENAC SUPPOSITORY ADMINISTRATED AFTER BIOPSY FOR THE CONTROL OF PAIN AND DISCOMFORT IN TRANSRECTAL ULTRASONOGRAPHY-GUIDED PROSTATE BIOPSY

Amaç: Transrektal ultrasonografi eşliğinde prostat biyopsilerinde (TRUS-Bx) işlem bitiminde uygulanan diclofenac supozituarın hastalarda ağrı ve rahatsızlık kontrolü üzerine olan etkisi araştırılmıştır. Gereç ve yöntem: Anormal parmakla rektal inceleme ve/veya yüksek serum PSA değeri nedeni ile TRUS-Bx yapılan 100 olgu çalışmaya alındı. TRUS-Bx, sadece rektum içine intrarektal 20 cc (çift uygulama) %2'lik lidokain jel (5 cc perianal bölgeye, kalan 15 cc rektum içine) uygulamasını takiben TRUS eşliğinde 18 Gauge Tru-cut biyopsi iğnesiyle, 10-12 kadranda gerçekleştirildi. Ellibeş hastaya işlem bitiminde rektal olarak 100 mg diclofenac sodyum (Voltaren® suppozituar) verildi. Kırkbeş hastaya ek ilaç verilmedi. Biyopsi sonrası, vizüel analog skala (VAS) kullanılarak ağrı ve rahatsızlık skorları işlem sonrası ilk 12 saat sonunda diclofenac alan ve almayan gruplarda karşılaştırıldı. Bulgular: Biyopsi sonrası ortalama ağrı ve rahatsızlık skorları diclofenac alan grupta sırasıyla 2 ± 0,9 ve 2,4 ± 0,7 olarak tespit edilirken tedavisiz grupta sırasıyla 1,9 ± 1 ve 2,2 ± 1,1 olarak bulundu. İşlem sonrası ilk 12 saatlik değerlendirmede diclofenac alan grupta ağrı ve rahatsızlık skorlarının (0,9 ± 0,8, 1,1 ± 0,9) tedavisiz gruba (1,3 ± 0,6, 1,4 ± 0,8) göre daha düşük olduğu görüldü. Gruplar karşılaştırıldığında 12. saatteki ağrı skorları arasındaki farkın istatistiksel olarak anlamlı olduğu saptandı (p=0,01) rahatsızlık skorlarında fark gözlenmesine rağmen istatistiksel olarak anlamlı düzeyde değildi (p= 0,084). Her iki grup arasında yaş, önceki biyopsi sayısı, kor biyopsi sayısı, prostat hacmi, biyopsi öncesi serum PSA düzeyi ve komplikasyonlar bakımından anlamlı farklılık saptanmadı. Voltaren alan gruptaki hastalar biyopsi sonrasında daha rahat bir gün geçirdiklerini ifade ettiler. Sonuç: TRUS biyopsi yapılan hastalarda tek doz diclofenac suppozituar etkin, güvenli bir şekilde işlem sonrası dönemde ağrı kontrolünü sağlamakta, hastaya konfor ve hayat kalitesinde artış sağlamaktadır. SUMMARY Objective: Transrectal ultrasonography-guided prostate biopsy (TRUS-Bx) is the gold standart for the diagnosis of prostate cancer. There are various methods defined in the current literature for the control of pain dring this procedure. In this study we have evaluated the efficacy of intrarectal administration of voltaren suppository administered at the end of biopsy for control of pain and discomfort. Material and method: 100 consecutive men underwent TRUS-Bx prostate biopsies for serum PSA elevation and/or suspicious digital rectal examination findings for prostate cancer were included in this study. TRUS-Bx were performed with 18 G Trucut biopsy needle from 10-12 cores after intrarectal administration of 20 cc (twice) %2 Lidocaine gel (5 cc on perianal region, 15 cc into the rectum). Fifty-five patients received voltaren treatment at the end of biopsy. No additional treatment were given in the second group of 45 patients. After the biopsy; a self-administrated 10-point linear visual scale was used to determine and compare the pain and discomfort scores of the two groups (diclofenac and no treatment) at 12 hour after biopsy. Results: The mean pain and discomfort scores after the biopsy whom were given 100 mg voltaren were 2 ± 0.9 and 2.4 ± 0.72.0; for no treatment group these scores were 1.9 ± 1 and 2.2 ± 1.1 respectively. The 12 hour evaluation showed that pain and discomfort scores in voltaren group (0.9 ± 0.8 and 1.1 ± 0.9) were lower than no treatment group (1.3 ± 0.6 vs 1.4 ± 0.8). When two groups were compared, the difference for pain scores was statistically significant (p=0.01). Although discomfort scores at 12th hour diminished, the difference did not reach statistical significance (p=0.084). There were not any considerable differences between the two groups regarding the age, previously performed biopsies, the core numbers, prostate volume, pre-biopsy serum PSA values and the complications of the procedure. Patients in the voltaren arm expressed a more comfortable day after biopsy. Conclusion: Diclofenac suppository administration after biopsy for relief of pain during TRUS-Bx is an effective, safe and simple method and enhance patient comfort and quality of life

Infection dynamics of Theileria annulata over a disease season following cell line vaccination

Tropical theileriosis is a tick-borne haemoparasitic disease of cattle caused by the protozoan parasite Theileria annulata. Globally, the economic impact of the disease is immense and enhanced control measures would improve livestock production in endemic regions. Immunisation with a live attenuated vaccine is an effective and widely used control method, however, the repeated use of live vaccines may have an impact on the field parasite population at a genetic level. Additionally, there has been an increasing number of reports of vaccine breakthrough cases in recent years. Thus, the present study was designed to evaluate the genetic composition of a parasite population over a disease season in a locality where live cell line vaccination is practised. A diverse range of parasite genotypes was identified and every T. annulata positive cattle blood sample harboured multiple parasite genotypes. An alteration in the major genotype and an increasing multiplicity of infection in individual animals was observed over the course of the disease season. Vaccination status was found not to effect within-host multiplicity of infection, while a significantly higher number of genotypes was detected in grazed cattle compared to non-grazed ones. A degree of genetic isolation was evident between parasite populations on a micro-geographic scale, which has not been reported previously for T. annulata. Analysis of parasite genotypes in vaccinated animals suggested only a transient effect of the vaccine genotype on the genetic diversity of the T. annulata population. The vaccine genotype was not detected among clones of two vaccine ‘breakthrough’ isolates and there is no suggestion that it was responsible for disease. The obtained data indicated that in the system studied there is no apparent risk of introducing the vaccine genotype into the population with only a transient effect on the genetic diversity of the parasite population during the disease season

Molecular surveillance of Theileria parasites of livestock in Oman

Background: Theileriosis is one of the most prevalent infectious diseases of livestock in the Arabian Peninsula, and causes high rates of mortality and morbidity in sheep and cattle. However, there is a paucity of information on the distribution of Theileria spp. over the whole region and their impact on different hosts. The present study carried out a country-wide molecular survey for Theileria spp. of livestock in Oman across four governorates. The aim of the survey was to define the prevalence of Theileria spp. in cattle, sheep and goats, highlight risk factors for infection and identify the main tick species involved in parasite transmission. Material and methods: A total of 2020 animals were examined in the survey consisting of sheep [n = 592], goats [n = 981] and cattle [n = 447]. All three species were raised and co-grazed on the same farms. Theileria parasites were detected using PCR-RFLP and RLB of the 18S rRNA gene. Cloning and sequencing of the 18S rRNA was carried out on 11 T. lestoquardi isolates from Ash-Sharqiyah, and Ad-Dhahira governorates, and phylogenetic relationships were inferred using additional sequences of T. lestoquardi, T. annulata and T. ovis available in GenBank. Results: Theileria spp. prevalence was 72.3%, 36.7% and 2.7% among cattle, sheep and goats, respectively. Strong similarity in results was obtained using RLB and PCR-RFLP for detection of Theileria spp. however, RLB detected a higher rate of mixed infection than PCR-RFPL (P &lt; 0.001). Theileria annulata was the only parasite detected in cattle, while sheep and goats carried T. ovis, T. lestoquardi and T. annulata as well as Theileria spp. OT1. Of the four Theileria spp. detected in small ruminants, overall T. ovis was most prevalent (sheep [33.4%], goats [2.0%]), whereas T. lestoquardi was less prevalent (sheep [22.0%], goats [0.5%]). A large proportion of infected sheep (19%) carried mixed infection of T. ovis and T. lestoquardi. However, single T. lestoquardi infections (3.0%) were less prevalent than T. ovis infections (14.5%). Risk of Theileria spp. infection was significantly higher for exotic breeds, relative to native breeds, of cattle (p = 0.00002) and sheep (p = 0.005). Phylogenetic analysis placed T. lestoquardi in Oman in the same clade as other T. lestoquardi strains isolated from the same regional area (Iraq and Iran). The main tick species, identified on the examined animals, Hyalomma anatolicum, was widely distributed and was found in all of the surveyed governorates. Conclusion: Theileria spp. are widespread in Oman with variable prevalence detected in different regions. Two economically important hosts, cattle and sheep are at high risk from virulent T. annulata and T. lestoquardi, respectively. The survey indicates extensive exposure to ticks and transmission of infection that has a significant economic impact. The higher prevalence of T. lestoquardi as mixed rather than single infection requires further investigation

Güneş enerjisi destekli zeolit iklimlendirme sistemi

TÜBİTAK MAG01.01.2009Güneş enerjisi ekonomik, temiz ve yenilenebilir bir enerji türüdür. Çevresel faktörler ve artmakta olan enerji talepleri dikkate alındığında bu enerji türünün kullanımı büyük önem kazanmaktadır. Güneş enerjili adsorplanmalı soğutma (GEAS) sistemleri gelecekte yaygın olarak kullanılması düşünülen ve ticarileşmesi için yoğun bir şekilde çaba sarf edilen termal enerji destekli soğutma sistemlerindendir. Bu sistemlerin başarılı bir şekilde çalışması büyük ölçüde adsorban- adsorplanan çiftinin doğru seçimine bağlıdır. Zeolit-su, zeolit-organik soğutucular, silika jel-su ve activated karbon-methanol katı adsorplanmalı güneş enerjili soğutma sistemlerinde kulanılabilecek uygun adsorban- adsorplanan çiftlerinden bazılarıdır. Adsorban malzemenin adsorplama kapasitesi, x=f (P, T), adsorpsiyon basıncı ve adsorban malzemenin sıcaklığı ile değişmektedir ve bu değişim çoğunlukla eş sıcaklık eğrileri çizilerek ifade edilmektedir. Bu çalışmada ilk olarak, zeolit-su çalışma çiftine ait eş sıcaklık eğrilerini elde etmek için adsorpsiyon deney düzeneği tasarlanmış ve imal edilmiştir. Daha sonra, bu düzenek üzerinde bir takım deneyler yapılmıştır. Bu deneyler sonucunda, zeolit-su çalışma çiftine ait eş sıcaklık eğrileri, adsorpsiyon ve desorpsiyon prosesleri için farklı adsorban o sıcaklıkları(40-150 C)veadsorpsiyonbasınçları(0.87-7.38kPa)altındadeneyselolarakelde edilmiştir. Ayrıca, adsorpsiyon ve desorpsiyon prosesleri için elde edilen eş sıcaklık eğrilerine Dubinin–Astakhov denklemi uyarlanmıştır. Đkinci olarak, adsorpsiyon deneylerinden elde edilen sonuçlar çerçevesinde, zeolit-su çalışma çiftini kullanan güneş enerjisi destekli adsorpsiyonlu örnek soğutma grubu tasarlanmış ve imalatı gerçekleştirilmiştir. Daha sonra, adsorpsiyonlu örnek soğutma grubunun termal performansı farklı buharlaştırıcı sıcaklıklarında deneysel olarak incelenmiştir. Desorpsiyon prosesi sırasında zeolit yatağının yenilenmesi için gerekli enerji, güneş enerjisi yerine elektrik enerjisiyle ısıtılan ısı transfer sıvısının gövde ile adsorban yatak arasında dolaştırılmasıyla sağlanmıştır. Diğer bir ifade ile güneş enerjisi elektrik enerjisi kullanılarak benzeştirilmiştir. Deneyler sonucunda, soğutma grubunun COP değeri ortalama 0, 25 olarak bulunmuştur. Son olarak, GEAS sistemlerini başarısı çalışma çiftinin doğru seçiminin yanı sıra sistemde kullanılacak güneş toplaçlarının performansına ve ekonomik maliyetinede büyük ölçüde bağlıdır. Dolayısıyla bu çalışmada, soğutma sisteminin güneş enerjisi destekli olması sebebiyle bir yıl boyunca düzlemsel ve vakumlu boru tipi güneş toplaçlarının performansı Ankara ili iklim koşulları altında deneysel olarak incelenmiştir. Ayrıca, güneş enerjisi destekli zeolit-su çalışma çiftini kullanan xi adsorpsiyonlu soğutma sisteminin yıllık analizlerini yapmak üzere TRNSYS programı yardımıyla sayısal bir model tasarlanmıştır.Solar energy is economical, clean and renewable. The use of solar energy is gaining more attention due to environmental factors and increasing demand for energy. Solar powered adsorption cooling (SPAC) systems are considered to have a large potential for use in the future and extensive efforts have been expended to make the thermal powered adsorption cooling systems commercial. The successful operation of these systems mostly depends on the correct choice of the adsorbent-adsorbate working pair. Zeolite-water, zeolite-organic refrigerants, silica gel-water and activated carbon-methanol are some of the suitable adsorbent-adsorbate pairs that can be used in solar powered adsorption cooling systems. Adsorption capacity of the adsorbent material, x=f (P, T), varies with the adsorption pressure and adsorbent temperature and this variation is commonly represented by isotherms of the adsorbent investigated. In this study, firstly, an adsorption experimental set-up was designed and constructed to obtain the isotherms of a natural zeolite-water working pair. After that, a set of experiments was conducted using this set-up. As a result of these experiments, isotherms of the zeolite-water pair were obtained experimentally under various adsorbent o temperatures (40-150 C) and adsorption pressures (0.87-7.38 kPa). In addition, the Dubinin– Astakhov equation was used to fit the isotherm data that were obtained for adsorption and desorption processes. Secondly, within the framework of the results of the adsorption experiments, a prototype of the solar powered adsorption cooling system using the natural zeolite-water working pair was designed and constructed. Afterwards, the thermal performance of the prototype was investigated experimentally under different evaporation temperatures. In these experiments, during the desorption process, the solar energy that is needed to dry out the saturated adsorbent was simulated by using electrical energy. As a result, the average COP value of the prototype studied was found as 0,25. Finally, in addition to the correct choice of the adsorbent-adsorbate pair, the success of the (SPAC) systems depends largely on the thermal performance and cost of the solar collectors. Therefore, in this study, the performance of flat plate and evacuated tube collectors were investigated under the climatic conditions of Ankara for one year. Additionally, a numerical model of the solar powered adsorption cooling system using zeolite-water pair was developed with the help of the TRNSYS program to analyze the annual performance of this system