bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding The Effect Of Noise, Vibration And Seat Discomfort Towards A Passenger’s Vehicle Driver Through Self–reported Survey
Authors: Daruis Dian Darina Indah , Md Deros Baba , Mohd Noor Mohd Jailani
Published: January 2013

Satu tinjauan berasaskan soal selidik atas talian telah dijalankan untuk mendapatkan maklumat berkenaan ketidakselesaan pemanduan kenderaan penumpang pemandu Malaysia. Faktor ketidakselesaan yang diselidiki ialah hingar, getaran dan tempat duduk pemandu. Untuk hingar dan getaran, didapati bahawa responden perempuan lebih tidak selesa untuk faktor berkaitan dengan getaran manakala responden lelaki lebih tidak selesa untuk faktor berkaitan hingar. Tiada perbezaan ketara antara ketidakselesaan untuk hingar dan getaran ketika pegun mahupun memecut. Berkenaan ketidakselesaan tempat duduk pemandu, didapati bahawa lebih ramai responden mengalami ketidakselesaan atau kesakitan di bahagian atas belakang. Perbezaan untuk respon ketidakselesaan bagi bahagian badan berlainan antara pemandu lelaki dan perempuan terutamanya disebabkan oleh faktor antropometri. Kedua–dua pemandu lelaki dan perempuan mengalami ketidakselesaan akibat hingar, getaran dan tempat duduk tetapi dengan sensitiviti yang berbeza untuk faktor dan bahagian tubuh yang berlainan. Daripada kajian ini, tiada perbezaan ketara yang dijumpai untuk kesuluruhan ketidakselesaan antara kedua–dua jantina. Meskipun ia berbentuk laporan kendiri, keputusannya adalah selari dengan penemuan daripada kajian–kajian literatur.

Kata kunci: Hingar; getaran; tempat duduk pemandu; ketidakselesaan; tinjauan; soal selidik

An online questionnaire–based survey was conducted to gather information regarding driving discomfort of Malaysian passengers’ vehicle driver. The discomfort factors investigated were noise, vibration and driver’s seat. For the noise and vibration, it was found that women respondents feel more discomfort for vibration related factors while men respondents feel more discomfort for noise related factors. There was no significant difference between discomfort for noise and vibration during idle or accelerating conditions. Regarding driver’s seat discomfort, it was found that more respondents had experienced discomfort or pain at the upper back. The differences of discomfort responses for different body parts between men and women drivers were mainly caused by anthropometrical factor. Both men and women drivers experience noise, vibration and seat discomfort, however with different levels of sensitivity for different factors and body parts. From this study, no significant difference was found on overall discomfort between genders. Although it is self–reported, the result is in–line with the findings from the literatures.

Key words: Noise; vibration; driver seat; discomfort; survey; questionnaire
Reading Readiness Test For Kindergarten Children
Authors: Yeo Kee Jiar , Md. Johan Othman
Published: January 2013

Belajar membaca ialah suatu proses perkembangan yang berlaku secara berterusan dan kesediaan merupakan konsep yang wujud dalam pelbagai peringkat belajar membaca tersebut. Kesediaan membaca pula biasanya dikatakan sebagai peringkat paling awal dalam kemahiran membaca secara tidak formal yang membabitkan kanak-kanak. Kesediaan membaca melibatkan tret asas umum yang dapat membantu kanak–kanak memulakan alam akademiknya tanpa banyak menghadapi masalah. Sebagai usaha mengkaji kebolehan aspek kognitif dalam kemahiran membaca, ujian kesediaan membaca dalam bahasa Melayu telah dibangunkan. Ujian ini merangkumi enam aspek, iaitu diskriminasi visual, kesedaran fonologi, huruf dan hubungan huruf–bunyi, melengkapkan ayat berpandukan huruf, kata pandang–sebut, dan pemahaman lisan. Ujian ini telah diberikan kepada 130 orang kanak–kanak tadika yang dipilih secara rawak daripada enam buah tadika untuk menentukan kestabilan psikometrik ujian tersebut. Analisis uji–uji semula yang dijalankan menunjukkan bahawa ujian yang dibangunkan mempunyai kebolehpercayaan yang agak tinggi, iaitu lebih daripada 0.80, justeru menunjukkan kegunaan pragmatis ujian ini. Diharapkan ujian ini dapat membantu pihak tadika dalam mengenal pasti kanak–kanak yang memerlukan penumpuan khusus dalam proses pembelajaran merkea, terutamanya dalam aspek membaca.

Kata kunci: Kesediaan; kesediaan membaca; ujian kesediaan membaca

Learning to read is an on–going developmental process and readiness is just a concept in the various stages of learning to read. Reading readiness is often referred as the earliest stage of informal reading skills that involve young children. It is the basic common traits which would help a child to begin his academic endeavour without much difficulties. To study the ability of cognitive aspect on reading, a reading readiness test in bahasa Melayu was developed. This test consists of six aspects, namely visual discrimination, phonological awareness, letter and letter–sound relationship, aural cloze with letter, sight words, and listening comprehension. This test was given to 130 kindergarten children randomly selected from six kindergartens to determine its psychometric stability. A test–retest analysis shows that the test has a fairly high reliability of more than 0.80, hence suggests its pragmatic utility. It is hoped that the test would enable kindergarten authority in identifying students who need special attention in their learning process, specifically in reading.

Key words: Readiness; reading readiness; reading readiness test
Ujian Pembakaran Propelan Roket Pepejal
Authors: Mohd Jaafar Mohammad Nazri , Wan Ali Wan Khairuddin , Mohamed Zahri Ahmad Saufi
Published: January 2013

Komposisi laker dan bahan api yang digunakan dalam fabrikasi propelan pepejal mempengaruhi kadar pembakaran. Kajian ini melihat pengaruh mengubah peratusan komposisi kedua-dua bahan tadi. Hasil ujikaji yang diperolehi, menunjukkan bahawa kadar pembakaran berkurangan dengan pertambahan peratusan laker apabila bahan api dimalarkan pada 29%. Bagaimanapun, apabila laker ditetapkan kepada 22% dan komposisi bahan api diubah-ubah, kadar pembakaran menunjukkan plot parabola dengan komposisi optimum bahan api pada 28.6%.

Kata kunci: Kalium nitrat; sulfur; aluminium; kadar pembakaran; roket pepejal

The composition of lacquer and fuel used during fabrication of solid propellant affects the burning rates. This study shows the effect of varying the percentage composition of both items. Results obtained show that the burning rates reduce with increase in laker percentage when fuel was set constant at 29%. However; when lacquer was set constant at 22% and at varied fuel compositions, the burning rates show a parabolic plot with the optimum composition at 28.6% fuel.

Key words: Kalium nitrate; sulfur; aluminium; burning rate; solid rocket
Statistical Vibration Based Damage Identification Using Artificial Neural Network
Authors: Bakhary Norhisham
Published: January 2013

Artificial Neural Network (ANN) telah digunakan dengan meluas bagi tujuan mengesan kerosakan dalam struktur menggunakan data–data mod dari gegaran. Walau bagaimanapun, ketidakpastian yang wujud dalam model unsur terhingga dan data dari lapangan yang tidak dapat dielakkan boleh menyebabkan kesilapan dalam meramalkan magnitud dan lokasi kerosakan. Dalam kajian ini kaedah statistik digunakan untuk mengambil kira ketidakpastian ini. ANN digunakan untuk meramalkan parameter–parameter kekukuhan dari frekuensi dan mod bentuk bagi sesebuah struktur. Untuk mengambil kira ketidakpastian dalam ramalan, kaedah statistik digunakan di mana kaedah Rossenblueth point estimation diperbandingkan dengan kaedah Monte Carlo diaplikasikan bagi mengambil kira ketidakpastian ini. Keputusan menunjukkan bahawa dengan mengambil kira ketidakpastian dalam membuat ramalan menggunakan ANN, kerosakan boleh diramalkan pada tahap keyakinan yang tinggi.

Kata kunci: Artificial neural network; ketidakpastian; kesilapan rawak

Artificial Neural Network (ANN) has been widely applied to detect damages in structures based on structural vibration modal parameters. However, uncertainties that inevitably exist in finite element model and measured vibration data might lead to false or unreliable prediction of structural damage. In this study, a statistical approach is proposed to include the effect of uncertainties in the ANN algorithm for damage prediction. ANN is used to predict the stiffness parameters of structures from measured structural vibration frequencies and mode shapes. Uncertainties in the measured data and finite element model of the structure are considered in the prediction. The statistics of the identified parameters are determined using Rossenblueth’s point estimation method and verified by Monte Carlo simulation. The results show that by considering these uncertainties in the ANN model, the damages can be detected with a higher confidence level.

Key words: Artificial neural network; uncertainties; random error
Diagnostic Thermoelectric Cooler Performance In Diode Pumped Solid State Laser
Authors: Bidin Noriah , Wan Razali Wan Aizuddin
Published: January 2013

Sistem penyejukan termoelektrik (TEC) amat penting untuk menstabilkan keluaran DPSS laser. Tujuan kajian ini adalah untuk mengenal pasti prestasi TEC bagi sistem DPSS laser. Laser diod (LD) berkuasa tinggi digunakan sebagai sumber pengepaman. Arus pengepaman diubah dan suhu bagi LD dan KTP dirakamkan. Arus ambang untuk DPSS laser beroperasi adalah 7 A. Suhu bagi LD didapati bertambah dengan cepat sebelum arus ambang dicapai. Kemudiannya berada dalam keadaan stabil pada suhu 25.4°C. Berbeza dengan hablur KTP yang mengalami tiga fasa sebelum mencapai suhu stabil. TEC berjaya mengawal suhu KTP laser pada suhu bilik iaitu 25.4°C selepas dipam dengan arus pengepaman yang lebih besar dari 18 A.

Kata kunci: Penyejukan termoelektrik; DPSS Laser; laser diod; hablur KTP; suhu

Thermoelectric cooler (TEC) system is important in order to stabilize the output of Diode Pumped Solid State Laser (DPSS) laser. The aim of this study is to diagnose the performance of TEC in DPSS system. High power diode laser (DL) driver was utilized as a pumping source. The current of the driver was verified and the temperature of the DL and KTP were measured. The threshold current for DPSS laser was obtained at 7 A. The temperature of diode laser was found drastically increase before threshold current. Beyond that point the temperature remained constant at 25.4°C. However in KTP crystal, three phases produced before achieving the same constant temperature of DL. Thus TEC was effectively controlled the temperature of KTP at ambient temperature of 25.4°C after diode laser was pumped with current greater than 18 A.

Key words: Thermoelectric cooler; DPSS Laser; diode laser; KTP crystal; temperature
Evaporated Palm Oil Cracking To Gasoline Over Zeolite Catalysts
Authors: Siregar Tirena Bahnur , Amin Nor Aishah Saidina
Published: January 2013

Peretakan bermangkin minyak kelapa sawit kepada gasolin menggunakan H–ZSM–5 dan H–Beta dijalankan pada tekanan atmosfera dan kadar alir mengikut berat 2.5 jam–1. Suhu tindak balas ditetapkan dalam julat 450°C to 525°C. Mangkin yang dikalsinkan telah dicirikan menggunakan teknik pembelauan sinar X, penjerapan piridina–spektrofotometri inframerah dan penjerapan nitrogen. Hasil cecair dan gas dianalisis menggunakan kromatografi gas (FID) dan (TCD). Peningkatan suhu tidak balas meninggikan penukaran minyak kelapa sawit. Penukaran minyak kelapa sawit dan kepemilihan gasolin tertinggi diperolehi dengan mangkin H–ZSM–5, masing–masing ialah 96.12% berat dan 29.92% berat. Walaupun penukaran minyak kelapa sawit dan kepemilihan gasolin untuk kedua–dua mangkin adalah tinggi, tetapi H–ZSM–5 menunjukkan hasil yang lebih baik berbanding H–Beta pada semua suhu. Gasolin yang dihasilkan menggunakan H–ZSM–5 mempunyai kandungan naftena yang tinggi, diikuti oleh isoparafin, olefin, aromatik dan sedikit paraffin, manakala gasolin yang terhadil menggunakan H–Beta mengandungi olefin, naftena, paraffin dan aromatik. Hasil sampingan utama adalah gas yang terdiri daripada komponen C1–C3 menggunakan H–ZSM–5 dan C3–C4 menggunakan H–Beta

Kata kunci: Zeolit; H–ZSM–5; H–Beta; peretakan; minyak kelapa sawit; gasolin

The catalytic cracking of palm oil to gasoline over H–ZSM–5 and H–Beta was studied in fixed bed reactor operated at atmospheric pressure and weight hourly space velocity (WHSV) of 2.5 h–1. The reaction temperature was varied between 450°C to 525°C. The calcined catalysts were characterized using X–Ray Diffraction (XRD), Pyridine Adsorption–Infrared Spectrophotometry (Py–IR) and Nitrogen Adsorption (NA) methods. The liquid and gaseous products were analyzed using (FID) and (TCD) gas chromatography respectively. Increase in reaction temperature led to higher palm oil conversion. The highest conversion and gasoline selectivity obtained at 525°C were 96.12 wt% and 29.92 wt% respectively with H–ZSM–5. Although the conversion and the gasoline selectivity of both catalysts was high, but H–ZSM–5 performed better than H–Beta at all temperature range. Gasoline produced using H–ZSM–5 consisted mainly of naphthenes beside isoparaffins, olefins, aromatics and a small amount of paraffins, while the gasoline obtained by using H–Beta contained olefins, naphthenes, paraffins and aromatics. Gas was the major side product, which consisted mainly of C1–C3 for using H–ZSM–5 and C3–C4 compounds for using H–Beta.

Key words: Zeolite; H–ZSM–5; H–Beta; cracking, palm oil; gasoline
Immobilization Of Glucose Oxidase In Freeze – Thawed PVA And PVA/TMOS Membrane
Authors: Abdul Aziz Azila , Jusoh Norhana , Ashari Mohd. Azizul , Hassan Norhasliza
Published: January 2013

Dalam projek ini, dua kaedah penyekat–gerakan enzim glukosa oksidase (GOD) bagi biosensor glukosa amperometrik berdasarkan peroksida telah dikaji. Bagi kaedah penyekat–gerakan yang pertama, glukosa oksidase telah disekat–gerak dalam polivinilalkohol (PNA) dibeku–cair pada tiga kepekatan PVA yang berbeza (5%, 10% dan 15% PVA). Kepekatan PVA yang lebih tinggi mampu menyekat–gerak enzim di dalam membran dengan lebih baik. Namun, kepekatan PVA yang lebih tinggi tidak semestinya mempunyai korelasi yang baik dengan aktiviti enzim. Membran PVA–GOD dibeku–cair dengan 10% PVA menunjukkan sensitiviti yang paling baik kepada glukosa. Prestasi membran PVA–GOD dibeku–cair dengan 15% PVA dan 5% PVA adalah hampir sama. Bagi kaedah penyekat–gerakan yang kedua, GOD disekat–gerak dalam PVA tetrametoksisilan (TMOS) pada kepekatan (3–glisidoksipropildimetiletoksi) silan yang berbeza. Bagi membran yang disediakan menggunakan 1:1 (TMOS: 3GPDES), peratusan enzim aktiviti yang tinggal selepas hari ke 40 ialah lebih kurang 51%. Membran yang disediakan menggunakan 1:2 (TMOS: 3GPDES) dan 1:3 (TMOS:3GPDES) adalah agak stabil dengan masing–masing sebanyak 69% dan 58% peratusan enzim aktiviti yang tinggal selepas hari ke 40. Keseluruhannya, biosensor glukosa telah menunjukkan prestasi yang memberangsangkan.

Kata kunci: Biosensor; glukosa; peroksida; kepekatan

In this work, two methods of glucose oxidase (GOD) immobilization for peroxide based glucose biosensor had been investigated. For the first immobilization method, GOD was immobilized in freeze–thawed poly (vinyl alcohol) (PVA) at three different PVA concentrations (5%, 10% and 15% PVA). The higher the PVA concentration used for immobilization, the better the retention of the enzyme in the membrane. Nevertheless, higher PVA concentration did not necessarily correlate well with enzyme activity. Freeze–thawed PVA–GOD membranes with 10% PVA showed the highest sensitivity to glucose. The performances of freeze–thawed PVA–GOD membranes with 15% and 5% PVA was comparable. For the second immobilization method, GOD was immobilized within PVA/tetramethoxysilane (TMOS) matrix with different (3–glycidoxypropyldimenthylethoxy) silane (3GPDES) concentrations. For the membranes prepared with 1:1 (TMOS: 3GPDES) volumetric ratio, the percentage of enzyme activity remaining at day 40 was about 51%. Meanwhile, membrane prepared with 1:2 (TMOS: 3GPDES) and 1:3 (TMOS: 3GPDES) were quite stable with 69% and 58% of enzyme activity remaining at day 40, respectively. Overall, the glucose biosensor showed very promising performances.

Key words: Biosensor; peroxide; temperature; concentration
Hubungan Antara Kemahiran Berfikir Kritis Dengan Pencapaian Akademik Dalam Kalangan Pelajar Fakulti Pendidikan Universiti Teknologi Malaysia
Authors: Ali Marlina , Noordin Shaharom
Published: January 2013

Kajian ini dijalankan bertujuan untuk menentukan perkaitan di antara kemahiran berfikir kritis dengan Purata Nilai Gred Kumulatif (PNGK) dalam kalangan pelajar yang mengikuti program pendidikan Fizik di Universiti Teknologi Malaysia. Seramai 109 orang pelajar tahun satu dan empat program Pendidikan Fizik terlibat dalam kajian ini iaitu 26 orang pelajar lelaki dan 83 pelajar perempuan. Julat umur pelajar adalah di antara 19 hingga 28 tahun. Alat kajian yang digunakan dalam kajian ini ialah Watson Glaser Critical Thinking Appraisal (WGCTA–A). Korelasi Pearson–r merupakan statistik utama yang digunakan dalam kajian ini. Keputusan kajian menunjukkan bahawa terdapat pertalian yang bererti antara kemahiran berfikir kritis dengan CPA pelajar pada aras .05. Kemahiran interpretasi merupakan aspek WGCTA yang bererti dalam meramal PNGK pelajar berbanding kemahiran membuat inferens, mengusul periksa andaian, membuat deduksi dan penilaian hujah. Seterusnya, hasil kajian menunjukkan tidak terdapat pertalian yang bererti di antara tahun pengajian dengan tahap kemahiran berfikir kritis pelajar.

Kata kunci: Kemahiran berfikir kritis; WGCTA; pelajar universiti; fizik; guru pelatih

This study was conducted to determine the relationship between critical thinking skills and among students in the physics education program at the Universiti Teknologi Malaysia. A total of 109 students from year one and four from physics education program, which consists of 26 boys and 83 girls involved in the study. The age range of students involved was between 19 to 28 years. The instrument used in this study was the Watson Glaser Critical Thinking Appraisal (WGCTA–A). A Pearson correlation–r was the main statistics used in this study. Results showed that there was a significant relationship between critical thinking skills and CPA of students at the level of .05. Interpretation was significant in predicting student’s CPA as compared to other skills in WGCTA such as inference, recognition of assumptions, deduction, and evaluation of arguments. Next, the finding showed no significant relationship between years of study with the students’ critical thinking skills.

Key words: Critical thinking; WGCTA; university students; physics; trainee teachers
Twitch interpolation: superimposed twitches decline progressively during a tetanic contraction of human adductor pollicis
Authors: Gandevia S. C. , McNeil C. J. , Carroll T. J. , Taylor J. L.
Published: January 2013

Key points

The size of an interpolated muscle twitch during a voluntary muscle contraction is used to assess the extra force that the central nervous system can harness from the muscle with volition. During human exercise, this interpolated twitch commonly increases in size and this reduced voluntary activation of the muscle is termed ‘central’ fatigue.

Recent work on isolated mouse muscle fibres suggests an alternative ‘peripheral’ explanation for the increased twitch based on altered sensitivity to intracellular calcium. We tested this possibility with tetanic stimulation of the ulnar nerve while measuring thumb adductor force.

During maximal tetani lasting 1 min at 30 Hz (or 3 min at 15 Hz), muscle force declined (i.e. peripheral fatigue developed) but the relative and absolute size of superimposed twitches declined progressively. They did not increase as predicted from the mouse study.

Twitch interpolation can reveal central fatigue during voluntary muscle contractions.

Abstract  The assessment of voluntary activation of human muscles usually depends on measurement of the size of the twitch produced by an interpolated nerve or cortical stimulus. In many forms of fatiguing exercise the superimposed twitch increases and thus voluntary activation appears to decline. This is termed ‘central’ fatigue. Recent studies on isolated mouse muscle suggest that a peripheral mechanism related to intracellular calcium sensitivity increases interpolated twitches. To test whether this problem developed with human voluntary contractions we delivered maximal tetanic stimulation to the ulnar nerve (≥60 s at physiological motoneuronal frequencies, 30 and 15 Hz). During the tetani (at 30 Hz) in which the force declined by 42%, the absolute size of the twitches evoked by interpolated stimuli (delivered regularly or only in the last second of the tetanus) diminished progressively to less than 1%. With stimulation at 30 Hz, there was also a marked reduction in size and area of the interpolated compound muscle action potential (M wave). With a 15 Hz tetanus, a progressive decline in the interpolated twitch force also occurred (to ∼10%) but did so before the area of the interpolated M wave diminished. These results indicate that the increase in interpolated twitch size predicted from the mouse studies does not occur. Diminution in superimposed twitches occurred whether or not the M wave indicated marked impairment at sarcolemmal/t‐tubular levels. Consequently, the increase in superimposed twitch, which is used to denote central fatigue in human fatiguing exercise, is likely to reflect low volitional drive to high‐threshold motor units, which stop firing or are discharging at low frequencies.
Breast density measurements with ultrasound tomography: A comparison with film and digital mammography
Authors: Duric Neb , Boyd Norman , Littrup Peter , Sak Mark , Myc Lukasz , Li Cuiping , West Erik , Minkin Sal , Martin Lisa , Yaffe Martin , Schmidt Steven , Faiz Muhammad , Shen Jason , Melnichouk Olga , Li Qing , Albrecht Teri
Published: January 2013

Purpose:

To investigate the use of the whole‐breast sound speed measurement as a marker of breast density (BD), a known risk factor for breast cancer.

Methods:

As part of an ongoing study of breast cancer detection, 249 patients were scanned with a clinical prototype that operates on the principles of ultrasound tomography. Typically, 40–100 sound speed tomograms were reconstructed from the scan data, corresponding to the entire volume of the breast of each patient. The data were used to estimate the volume averaged sound speed (VASS) of the breast for each patient. The corresponding mammograms were used to calculate mammographic percent density (MPD) usingCUMULUS software. Film mammograms were available for 164 patients while 85 digital mammograms were available for the remaining patients. Standard statistical techniques were used to determine associations of breast sound speed with a variety of mammographic measures such as percent density, area of dense tissue, and area of nondense tissue. Furthermore, associations of breast sound speed with continuous variables such as age and weight and dichotomous variables such as parity and menopausal status were also assessed.

Results:

VASS was found to be significantly associated with MPD. The Spearman correlation coefficient (rs) between VASS and MPD was found to be 0.77 and 0.71 for film and digital mammography, respectively. VASS was positively correlated with dense areas by mammography, both digital (rs = 0.46) and film (rs = 0.56). VASS was negatively associated with nondense area by mammography, both digital (rs = −0.58) and film (rs = −0.63). BD by all methods was less in postmenopausal than in premenopausal women. The MPD was lower in the postmenopausal group (by 6.6%, p < 0.08, for the digital group and 7.73%, p < 0.007, for the film group). The VASS was also lower in the postmenopausal group (by 15 m/s, p < 0.001 for the digital group and 8 m/s, p < 0.08, for the film group). The association of MPD with age was characterized with rs = −0.06 (p < 0.6) for digital mammography and rs = −0.53 (p < 0.002) for film mammography. For weight, the MPD associations were characterized by rs = −0.53 (p < 0.0001) for digital mammography and −0.38 (p < 0.0001) for film mammography. The association of VASS with age was rs = −0.33 (p < 0.002) for the digital group and −0.17 (p < 0.03) for the film group. For weight, the relationship was characterized with rs = −0.45 (p < 0.001) for the digital group and −0.37 (p < 0.0001) for the film group.

Conclusions:

The association between VASS and MPD is strong for both film and digital mammography, suggesting that VASS is a viable measure of breast density. This result sets the stage for future work that will focus on directly testing the association of VASS with breast cancer risk.
Negative Absolute Temperature for Motional Degrees of Freedom
Authors: Braun S. , Ronzheimer J. P. , Schreiber M. , Hodgman S. S. , Rom T. , Bloch I. , Schneider U.
Published: January 2013

Negative Is Hotter

A common-sense perception of temperature tells us that the lower the temperature, the colder it is. However, below absolute zero, there is a netherworld of negative temperatures, which are, counterintuitively, hotter than positive temperatures. Usually, such states are achieved in the laboratory and are characterized by a higher occupation of high-energy versus low-energy states. This is most easily done for systems that have a finite spectrum of energy states, bounded from above and below.

Braun
et al.

(p.
52
; see the Perspective by

Carr

) achieved negative temperature for a system in which its spectrum was only bounded on one side. Starting with a gas of
39
K bosonic atoms with repulsive interactions in a dipole trap and an optical lattice, a final state with negative temperature was reached where the atoms attract each other.
Dynamic Persistence of Antibiotic-Stressed Mycobacteria
Authors: Wakamoto Yuichi , Dhar Neeraj , Chait Remy , Schneider Katrin , Signorino-Gelo François , Leibler Stanislas , McKinney John D.
Published: January 2013

All About Noise

How individual cells behave within a larger “average” population can be surprising.

Wakamoto
et al.

(p.
91
) developed a method for investigating the consequences of phenotypic variability in single mycobacterial cells exposed to the pro-drug, isoniazid. Isoniazid needs to be activated by bacterial catalase. In the isoniazid–mycobacterium system, random fluctuations in catalase activity were important for cell survival. Because catalase is essential, it cannot be ablated; however, catalase activity pulsed randomly in the mycobacteria. Thus, a subpopulation of individual cells manage to avoid being killed by the activated antibiotic.
Getting Past Polyproline Pauses
Authors: Buskirk Allen R. , Green Rachel
Published: January 2013

A protein that associates with the ribosome alleviates stalling and stimulates translation of proline-rich motifs.

[Also see Reports by

Ude
et al.

and

Doerfel
et al.

]
China Partners With Gay Groups on HIV Screening
Authors: Hvistendahl Mara
Published: January 2013

Reaching men who have sex with men has long been a goal for the Chinese government. Now, it's becoming a reality with the help of a handful of community-based organizations.
A Boost for Lithium-Sulfur Batteries
Authors: Service Robert F.
Published: January 2013

They weren't ready in time for this holiday season's gadgets, but better lithium-ion batteries could be in the offing.
Space Solar Cells With A Down-to-Earth Cost
Authors: Service Robert F.
Published: January 2013

Researchers may have found a way to not only drop the cost of producing gallium arsenide cells, but to also drop the cost of the power they produce to near that of grid power from fossil fuels.
Genetic Characterization of Toxoplasma gondii Revealed Highly Diverse Genotypes for Isolates from Newborns with Congenital Toxoplasmosis in Southeastern Brazil
Authors: Carneiro Ana Carolina Aguiar Vasconcelos , Andrade Gláucia Manzan , Costa Júlia Gatti Ladeia , Pinheiro Breno Veloso , Vasconcelos-Santos Daniel Vitor , Ferreira Adriana Melo , Su Chunlei , Januário José Nélio , Vitor Ricardo Wagner Almeida
Published: January 2013

Recent studies of
Toxoplasma gondii
isolates from animals in Brazil have revealed high genetic diversity. Many of these isolates are virulent to mice. It is speculated that these isolates may also be virulent to humans. However, there is very limited data regarding
T. gondii
strains from human infection. Therefore, it is not clear whether there is any association between parasite genotypes and disease phenotypes. In this study, a total of 27
T. gondii
strains were isolated from humans with congenital toxoplasmosis in Minas Gerais state, Brazil. The genetic variability was assessed by restricted fragment length polymorphism in 11 loci (
SAG1
, 5′ plus 3′
SAG2
, alternative [alt.]
SAG2
,
SAG3
,
BTUB
,
GRA6
,
c22-8
,
c29-2
,
L358
,
PK1
, and
Apico
). Genetic analysis of 24 strains revealed 14 different genotypes, including 7 previously identified from animals and 7 new types. The widespread genotype BrII accounted for 29% (7/24) of the isolates and was the dominant genotype involved in this study. This is the first report of genotyping of
T. gondii
isolates obtained from blood samples from newborns with congenital toxoplasmosis. Genotypic characterization of these isolates suggests high genetic diversity of
T. gondii
in this human population in Brazil. Future studies are needed to determine the source of contamination of this human population.
Yersinia enterocolitica in Diagnostic Fecal Samples from European Dogs and Cats: Identification by Fourier Transform Infrared Spectroscopy and Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry
Authors: Stamm Ivonne , Hailer Mandy , Depner Barbara , Kopp Peter A. , Rau Jörg
Published: January 2013

Yersinia enterocoliticais the main cause of yersiniosis in Europe, one of the five main bacterial gastrointestinal diseases of humans. Beside pigs, companion animals, especially dogs and cats, were repeatedly discussed in the past as a possible source of pathogenicY. enterocolitica. To investigate the presence and types ofY. enterocoliticain companion animals, a total of 4,325 diagnostic fecal samples from dogs and 2,624 samples from cats were tested. The isolates obtained were differentiated by using matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) and Fourier transform infrared spectroscopy (FT-IR). IsolatedY. enterocoliticastrains were bioserotyped. The detection of theailgene by PCR and confirmation by FT-IR were used as a pathogenicity marker.Y. enterocoliticastrains were isolated from 198 (4.6%) of the dog and 8 (0.3%) of the cat fecal samples investigated. One hundred seventy-nine isolates from dogs were analyzed in detail. The virulence factor Ail was detected in 91.6% of isolates. Isolates of biotype 4 (54.7%) and, to a lesser extent, biotypes 2 (23.5%), 3 (11.2%), and 5 (2.2%) were detected. The remaining 8.4% of strains belonged to theail-negative biotype 1A. All 7 isolates from cats that were investigated in detail wereailpositive. These results indicate that companion animals could be a relevant reservoir for a broad range of presumptively human-pathogenicY. enterocoliticatypes. MALDI-TOF MS and FT-IR proved to be valuable methods for the rapid identification ofY. enterocolitica, especially in regard to the large number of samples that were investigated in a short time frame.
Evaluation of a Benchtop HIV Ultradeep Pyrosequencing Drug Resistance Assay in the Clinical Laboratory
Authors: Avidor Boaz , Girshengorn Shirley , Matus Natalia , Talio Hadass , Achsanov Svetlana , Zeldis Irene , Fratty Ilana S. , Katchman Eugene , Brosh-Nissimov Tal , Hassin David , Alon Danny , Bentwich Zvi , Yust Israel , Amit Sharon , Forer Relly , Vulih Shultsman Ina , Turner Dan
Published: January 2013

Detection of low-abundance drug resistance mutations (DRMs) of HIV-1 is an evolving approach in clinical practice. Ultradeep pyrosequencing has shown to be effective in detecting such mutations. The lack of a standardized commercially based assay limits the wide use of this method in clinical settings. 454 Life Sciences (Roche) is developing an HIV ultradeep pyrosequencing assay for their benchtop sequencer. We assessed the prototype plate in the clinical laboratory. Plasma samples genotyped by the standardized TruGene kit were retrospectively tested by this assay. Drug-treated subjects failing therapy and drug-naive patients were included. DRM analysis was based on the International AIDS Society USA DRM list and the Stanford algorithm. The prototype assay detected all of the DRMs detected by TruGene and additional 50 low-abundance DRMs. Several patients had low-abundance D67N, K70R, and M184V reverse transcriptase inhibitor mutations that persisted long after discontinuation of the drug that elicited these mutations. Additional patient harbored low-abundance V32I major protease inhibitor mutation, which under darunavir selection evolved later to be detected by TruGene. Stanford analysis suggested that some of the low-abundance DRMs were likely to affect the resistance burden in these subjects. The prototype assay performs at least as well as TruGene and has the advantage of detecting low-abundance drug resistance mutations undetected by TruGene. Its ease of use and lab-scale platform will likely facilitate its use in the clinical laboratory. The extent to which the detection of low-abundance DRMs will affect patient management is still unknown, but it is hoped that use of such an assay in clinical practice will help resolve this important question.
Detection of the A2058G and A2059G 23S rRNA Gene Point Mutations Associated with Azithromycin Resistance in Treponema pallidum by Use of a TaqMan Real-Time Multiplex PCR Assay
Authors: Chen Cheng-Yen , Chi Kai-Hua , Pillay Allan , Nachamkin Eli , Su John R. , Ballard Ronald C.
Published: January 2013

Macrolide treatment failure in syphilis patients is associated with a single point mutation (either A2058G or A2059G) in both copies of the 23S rRNA gene in
Treponema pallidum
strains. The conventional method for the detection of both point mutations uses nested PCR combined with restriction enzyme digestions, which is laborious and time-consuming. We initially developed a TaqMan-based real-time duplex PCR assay for detection of the A2058G mutation, and upon discovery of the A2059G mutation, we modified the assay into a triplex format to simultaneously detect both mutations. The point mutations detected by the real-time triplex PCR were confirmed by pyrosequencing. A total of 129 specimens PCR positive for
T. pallidum
that were obtained from an azithromycin resistance surveillance study conducted in the United States were analyzed. Sixty-six (51.2%) of the 129 samples with the A2058G mutation were identified by both real-time PCR assays. Of the remaining 63 samples that were identified as having a macrolide-susceptible genotype by the duplex PCR assay, 17 (27%) were found to contain the A2059G mutation by the triplex PCR. The proportions of macrolide-susceptible versus -resistant genotypes harboring either the A2058G or the A2059G mutation among the
T. pallidum
strains were 35.6, 51.2, and 13.2%, respectively. None of the
T. pallidum
strains examined had both point mutations. The TaqMan-based real-time triplex PCR assay offers an alternative to conventional nested PCR and restriction fragment length polymorphism analyses for the rapid detection of both point mutations associated with macrolide resistance in
T. pallidum
.
Evaluation of Brilliance MRSA 2 Agar for Detection of Methicillin-Resistant Staphylococcus aureus in Clinical Samples
Authors: Veenemans J. , Verhulst C. , Punselie R. , van Keulen P. H. J. , Kluytmans J. A. J. W.
Published: January 2013

We compared 2 chromogenic media (Oxoid
Brilliance
MRSA 2 agar [Thermo Fisher Scientific] and MRSA-ID [bioMérieux]) for the detection of methicillin-resistant
Staphylococcus aureus
(MRSA) in 1,368 hospital samples. For both media, broth enrichment was essential to obtain satisfactory diagnostic performance. Although with direct cultures only, the diagnostic performance (particularly sensitivity) of
Brilliance
MRSA 2 agar appears better than that of MRSA-ID, no difference in sensitivity or specificity between the media was detected after inclusion of an enrichment step.
Most Influenza A Virions Fail To Express at Least One Essential Viral Protein
Authors: Brooke Christopher B. , Ince William L. , Wrammert Jens , Ahmed Rafi , Wilson Patrick C. , Bennink Jack R. , Yewdell Jonathan W.
Published: January 2013

Segmentation of the influenza A virus (IAV) genome enables rapid gene reassortment at the cost of complicating the task of assembling the full viral genome. By simultaneously probing for the expression of multiple viral proteins in MDCK cells infected at a low multiplicity with IAV, we observe that the majority of infected cells lack detectable expression of one or more essential viral proteins. Consistent with this observation, up to 90% of IAV-infected cells fail to release infectious progeny, indicating that many IAV virions scored as noninfectious by traditional infectivity assays are capable of single-round infection. This fraction was not significantly affected by target or producer cell type but varied widely between different IAV strains. These data indicate that IAV exists primarily as a swarm of complementation-dependent semi-infectious virions, and thus traditional, propagation-dependent assays of infectivity may drastically misrepresent the true infectious potential of a virus population.
An Endothelial Cell-Specific Requirement for the
UL133-UL138
Locus of Human Cytomegalovirus for Efficient Virus Maturation
Authors: Bughio Farah , Elliott David A. , Goodrum Felicia
Published: January 2013

Human cytomegalovirus (HCMV) infects a variety of cell types in humans, resulting in a varied pathogenesis in the immunocompromised host. Endothelial cells (ECs) are considered an important target of HCMV infection that may contribute to viral pathogenesis. Although the viral determinants important for entry into ECs are well defined, the molecular determinants regulating postentry tropism in ECs are not known. We previously identified the
UL133-UL138
locus encoded within the clinical strain-specific UL
b
′ region of the HCMV genome as important for the latent infection in CD34
+
hematopoietic progenitor cells (HPCs). Interestingly, this locus, while dispensable for replication in fibroblasts, was required for efficient replication in ECs infected with the TB40E or fusion-inducing factor X (FIX) HCMV strains. ECs infected with a virus lacking the entire locus (
UL133-UL138
NULL
virus) complete the immediate-early and early phases of infection but are defective for infectious progeny virus production. ECs infected with
UL133-UL138
NULL
virus exhibited striking differences in the organization of intracellular membranes and in the assembly of mature virions relative to ECs infected with wild-type (WT) virus. In
UL133-UL138
NULL
virus-infected ECs, Golgi stacks were disrupted, and the viral assembly compartment characteristic of HCMV infection failed to form. Further, progeny virions in
UL133-UL138
NULL
virus-infected ECs inefficiently acquired the virion tegument and secondary envelope. These defects were specific to infection in ECs and not observed in fibroblasts infected with
UL133-UL138
NULL
virus, suggesting an EC-specific requirement for the
UL133-UL138
locus for late stages of replication. To our knowledge, the
UL133-UL138
locus represents the first cell-type-dependent, postentry tropism determinant required for viral maturation.
Characterization of the Uukuniemi Virus Group (Phlebovirus: Bunyaviridae): Evidence for Seven Distinct Species
Authors: Palacios Gustavo , Savji Nazir , Travassos da Rosa Amelia , Guzman Hilda , Yu Xuejie , Desai Aaloki , Rosen Gail Emilia , Hutchison Stephen , Lipkin W. Ian , Tesh Robert
Published: January 2013

Evolutionary insights into the phleboviruses are limited because of an imprecise classification scheme based on partial nucleotide sequences and scattered antigenic relationships. In this report, the serologic and phylogenetic relationships of the Uukuniemi group viruses and their relationships with other recently characterized tick-borne phleboviruses are described using full-length genome sequences. We propose that the viruses currently included in the
Uukuniemi virus
group be assigned to five different species as follows:
Uukuniemi virus
,
EgAn 1825-61 virus
,
Fin V707 virus
,
Chizé virus
, and
Zaliv Terpenia virus
would be classified into the
Uukuniemi
species;
Murre virus
,
RML-105-105355 virus
, and
Sunday Canyon virus
would be classified into a
Murre virus
species; and
Grand Arbaud virus
,
Precarious Point virus
, and
Manawa virus
would each be given individual species status. Although limited sequence similarity was detected between current members of the
Uukuniemi
group and
Severe fever with thrombocytopenia syndrome virus
(SFTSV) and
Heartland virus
, a clear serological reaction was observed between some of them, indicating that SFTSV and
Heartland virus
should be considered part of the
Uukuniemi virus
group. Moreover, based on the genomic diversity of the phleboviruses and given the low correlation observed between complement fixation titers and genetic distance, we propose a system for classification of the
Bunyaviridae
based on genetic as well as serological data. Finally, the recent descriptions of SFTSV and Heartland virus also indicate that the public health importance of the Uukuniemi group viruses must be reevaluated.
The Receptor-Binding Site of the Measles Virus Hemagglutinin Protein Itself Constitutes a Conserved Neutralizing Epitope
Authors: Tahara Maino , Ohno Shinji , Sakai Kouji , Ito Yuri , Fukuhara Hideo , Komase Katsuhiro , Brindley Melinda A. , Rota Paul A. , Plemper Richard K. , Maenaka Katsumi , Takeda Makoto
Published: January 2013

Here, we provide direct evidence that the receptor-binding site of measles virus (MV) hemagglutinin protein itself forms an effective conserved neutralizing epitope (CNE). Several receptor-interacting residues constitute the CNE. Thus, viral escape from neutralization has to be associated with loss of receptor-binding activity. Since interactions with both the signaling lymphocyte activation molecule (SLAM) and nectin4 are critical for MV pathogenesis, its escape, which results from loss of receptor-binding activity, should not occur in nature.
Individual N-Glycans Added at Intervals along the Stalk of the Nipah Virus G Protein Prevent Fusion but Do Not Block the Interaction with the Homologous F Protein
Authors: Zhu Qiyun , Biering Scott B. , Mirza Anne M. , Grasseschi Brittany A. , Mahon Paul J. , Lee Benhur , Aguilar Hector C. , Iorio Ronald M.
Published: January 2013

The promotion of membrane fusion by most paramyxoviruses requires an interaction between the viral attachment and fusion (F) proteins to enable receptor binding by the former to trigger the activation of the latter for fusion. Numerous studies demonstrate that the F-interactive sites on the Newcastle disease virus (NDV) hemagglutinin-neuraminidase (HN) and measles virus (MV) hemagglutinin (H) proteins reside entirely within the stalk regions of those proteins. Indeed, stalk residues of NDV HN and MV H that likely mediate the F interaction have been identified. However, despite extensive efforts, the F-interactive site(s) on the Nipah virus (NiV) G attachment glycoprotein has not been identified. In this study, we have introduced individual N-linked glycosylation sites at several positions spaced at intervals along the stalk of the NiV G protein. Five of the seven introduced sites are utilized as established by a retardation of electrophoretic mobility. Despite surface expression, ephrinB2 binding, and oligomerization comparable to those of the wild-type protein, four of the five added N-glycans completely eliminate the ability of the G protein to complement the homologous F protein in the promotion of fusion. The most membrane-proximal added N-glycan reduces fusion by 80%. However, unlike similar NDV HN and MV H mutants, the NiV G glycosylation stalk mutants retain the ability to bind F, indicating that the fusion deficiency of these mutants is not due to prevention of the G-F interaction. These findings suggest that the G-F interaction is not mediated entirely by the stalk domain of G and may be more complex than that of HN/H-F.
Primary amenorrhoea due to a rare cause: epidermolysis bullosa causing haematometra
Authors: Singh Chanchal , Tripathi Reva , Sardana Kabir , Mala Yedla Manikya
Published: January 2013

A 27-year-old woman with junctional epidermolysis bullosa (EB) presented with primary amenorrhoea and massive haematometra. Considering her severe physical handicap and anticipated problems in optimising menstrual hygiene, the patient and her parents opted for hysterectomy which was performed uneventfully. The patient was recovering well postoperatively until the eighth postoperative day when she developed acute dilation of stomach and unfortunately died on day 17.
Unusual presentation of a femoral stress fracture
Authors: Ejnisman Leandro , Wajnsztejn Andre , Queiroz Roberto Dantas , Ejnisman Benno
Published: January 2013

Stress fractures are common injuries in sports medicine. Among these fractures, femoral neck stress fractures frequently have a benign course, especially when it happens in the medial aspect of the neck. This case report describes a stress fracture of the medial aspect of the femoral neck that developed a complete fracture and underwent surgical fixation.
Management of oral submucous fibrosis by different surgical approaches: report of three cases
Authors: Agarwal Rashmi , Kaushal Ambrish , Singh Rajeev Kumar , Upadhyay Yogesh
Published: January 2013

Oral submucous fibrosis (OSMF) is an insidious chronic progressive disease of the oral cavity which is considered as a precancerous condition. The suggested aetiological factor is the practice of certain customs/habits of the inhabitants of South East Asia. As the disease progresses, the oral mucosa becomes stiff due to the formation of fibrotic bands in the cheek, ultimately leading to reduced mouth opening and trismus. The early form of the disease can be treated by medicinal means, however, advance form needs surgical excision of the fibrotic tissue bands. The defect created due to the excision needs to be repaired by various grafts including split thickness skin grafting, bilateral nasolabial flaps, palatal island flaps, tongue flaps, buccal fat pad graft and temporalis muscle flap graft. We present the management of trismus following OSMF by various surgical approaches in three cases.
Investigating the autonomic nervous system and cognitive functions as potential mediators of an association between cardiovascular disease and driving performance
Authors: Gaudet Jeffrey , Bélanger Mathieu F. , Corriveau Hélène , Mekary Said , Hay Dean , Johnson Michel J.
Published: January 2013

Cardiovascular disease (CVD) impacts the autonomic nervous system and cognitive functions related to activities of daily living, including driving an automobile. Although CVD has been linked to unsafe driving, mechanisms underlying this relationship remain elusive. The aim of this study was to examine the role of cognitive functions and the autonomic nervous system as potential mediators of driving performance. Nineteen individuals having recently suffered a cardiac event and 16 individuals with no history of CVD completed a simulated drive using a STISIM simulator to assess driving performance. Heart rate was recorded throughout testing using a Polar RS800CX heart rate monitor, and measures of executive, orienting, and alerting functions were obtained through the Attention Network Test. We used the Baron and Kenny analysis method to assess potential mediating effects of the relationship between CVD and driving performance. Executive function was the only potential mediator investigated to be associated with driving (p < 0.01) and CVD (p < 0.05); however, it did not appear to play a mediating role (p = 0.28). These results suggest that individuals with CVD exhibit decrements in complex cognitive tasks such as driving and that further research is needed to better understand the mechanisms underlying this relationship.