Tailoring crystallinity of electrospun Plla fibres by control of electrospinning parameters

Poly(L-lactic acid) (PLLA) fibers were fabricated by electrospinning. The effects of various electrospinning process parameters on the thermal properties, especially the crystallinity of the electrospun fibers were investigated. Thermal analysis of the fibers revealed that they exhibited degree of crystallinity ranging from 23% to 46% while that for the as-received granules was approximately 37%, suggesting that the crystallinity of electrospun PLLA fibres can be controlled by optimizing the electrospinning process. This finding is very important because crystallinity affects polymer properties such as degradation, stiffness,yield stress, modulus and tensile strength, solubility, optical and electrical properties which will in turn affect the behavior of these materials when they are utilized in energy,environment, defense and security applications. The results presented in this paper show that the degree of crystallinity of the electrospun fibers decreased with increasing the polymer solution concentration. Furthermore, an optimum electrospinning voltage at which maximum degree of crystallinity can be obtained was observed. At voltages higher or lower than the optimum electrospinning voltage, the degree of rystallinity will decrease or increase,respectively. The effect of the needle tip to collector distance (NTCD) on the degree of\ud crystallinity follows no predictable and consistent pattern

Shock induced boundary layer over a semi-infinite flat plate. Part 1: Flow in the immediate vicinity of the shock wave

Laminar, two dimensional boundary layer generated in immediate vicinity of plane shock wave moving over flat plate into gas initially at res

Bakteri ribosoomi modifitseeritud nukleosiidid

Väitekirja elektrooniline versioon ei sisalda publikatsioone.Ribosoomid on imepisikesed masinad, mis valmistavad geenides paikneva informatsiooni alusel valke. Ribosoomid on kõigis elusrakkudes üldehituselt sarnased kuigi detailides on ka palju erinevusi. Ribosoomid on keerulise ehitusega, koosnevad ribonukleiinhappest (rRNA) ja valkudest, kusjuures rRNA moodustab suurema osa ribosoomide massist. Päristuumsete organismide, sealhulgas ka inimeste, ribosoomid on suuremad ja keerulisema ehitusega kui bakterite ribosoomid, ent ribosoomide põhielemendid ja töömehanism on samad kõikides elusolendites. Kuna bakterite uurimine on tehniliselt ja eetiliselt lihtsam, on suurem osa informatsiooni ribosoomide ehituse ja töömehanismi aga ka ribosoomide enda valmistamise kohta saadud just bakteritest. rRNA koosneb pikast ribonukleosiidide (adenosiinist, guanosiinist, uratsiilist ning tsütosiinist) ahelatest. Ribosoomide sünteesimise käigus muudetakse mõningate ribonukleosiidide omadusi spetsiaalsete valkude, modifikatsiooniensüümide, poolt. Muudetud omadustega nukleosiide kutsutakse modifitseeritud nukleosiidideks. Modifitseeritud nukleosiidid esinevad kõikides ribosoomides ning paiknevad ribosoomi talitluse seisukohalt olulistes piirkondades, ent nende tähtsus ribosoomide töö seisukohalt on teadmata. Meie tuvastasime modifikatsiooniensüümi, RlmH, mis on eriline selle poolest, et modifitseerib soolekepikese (Escherichia coli) ribosoomi suurema alamühiku olulises piirkonnas paiknevat pseudouridiini, mis on omakorda modifitseeritud nukleosiid. Lisaks on RlmH huvitav selle poolest, et modifitseerib juba praktiliselt valminud ning võimalik et juba valku tootvat ribosoomi. RlmH on teadaolevalt ainuke valk, mis vajab ribosoomi ühe alamühiku rRNA modifitseerimiseks mõlemat alamühikut. Meie oleme iseloomustanud RlmH töö jaoks vajalikke tingimusi ja oleme selgitanud mehanisme, mis tagavad RlmH valgu erilisuse.Ribosomes are tiny machines that make proteins using the information stored in genes. The structure and mechanism of ribosomes is similar in all cells, but bacterial and eukaryotic (including human) ribosomes differ in details, eukaryotic ones are bigger, for instance. Ribosomes have a complicated structure; they are made of a large subunit and a small subunit both of which are made of ribonucleic acids (rRNA) and proteins. rRNA gives most of the mass to the ribosomes. Since it is both technically and ethically easier to study bacteria, most of the information about the structure and mechanisms of ribosomes as well as making the ribosomes themselves comes from them. The rRNA molecules are long chains put together of ribonucleosides (adenosine, guanosine, cytidine, and uridine). However, during making of the ribosomes but after the rRNA chain is already put together, some of the nucleosides in the chain are altered by specific proteins called modification enzymes. The altered nucleosides are called modified nucleosides and they are present in important parts of all ribosomes. However, the role of the modified nucleosides is unknown for the most part. We found that that the bacterial (Escherichia coli) modification enzyme RlmH is special because it modifies pseudouridine, which already is a modified nucleoside and is located in a very important part of the large subunit. In addition, RlmH is special because it is the only modification enzyme that requires both subunits of the ribosome to modify rRNA. In fact, RlmH modifies an almost finished ribosome that is possibly already making proteins. We have studied the conditions that RlmH requires to modify the rRNA and the mechanism behind its uniqueness

Shock induced boundary layer over a semi-infinite flat plate. Part 2: Complete problem

Numerical analysis of shock induced boundary layer flow on semi-infinite flat plate - Part

Technocracy, pseudoscience and performative compliance: the risks of privacy risk assessments. Lessons from NIST's Privacy Risk Assessment Methodology

Privacy risk assessments have been touted as an objective, principled way to encourage organizations to implement privacy-by-design. They are central to a new regulatory model of collaborative governance, as embodied by the GDPR. However, existing guidelines and methods remain vague, and there is little empirical evidence on privacy harms. In this paper we conduct a close analysis of US NIST's Privacy Risk Assessment Methodology, highlighting multiple sites of discretion that create countless opportunities for adversarial organizations to engage in performative compliance. Our analysis shows that the premises on which the success of privacy risk assessments depends do not hold, particularly in regard to organizations' incentives and regulators auditing capabilities. We highlight the limitations and pitfalls of what is essentially a utilitarian and technocratic approach, leading us to discuss alternatives and a realignment of our policy and research objectives.Comment: Working draft. A version of this paper was presented at the 16th International Conference on Computers, Privacy and Data Protection, May 24-26, 2023 in Brussels (Belgium

Hubungan Tingkat Pengetahuan Dan Dukungan Keluarga Terhadap Penerapan Inisiasi Menyusui Dini (IMD) Pada Ibu Di Wilayah Kerja Kelurahan Talang Betutu Palembang

Background: Early Initiation of Breastfeeding (EIBF) has the benefits to grow and develop infant immunity so that it can avoid the risk of death from immunity is still very vulnerable. Implementation of EIBF is not easy to do and one of the reason is the low level of knowledge of mother and family about the benefits of application of EIBF. It is known that the number of EIBF application coverage in Indonesia is still far from the target number (80%) which is only 42.7% while in South Sumatera 48.1%. Aim: The purpose of this study was to determine relationship level knowledge and family support on early initiation of breastfeeding (EIBF) to mother in work area Talang Betutu Palembang. Method: This study uses analitic survey design with cross sectional approach. This research use analitic survey design with cross sectional approach. Data analysis using Kendall Tau test with sampling technique is total sampling amounted to 40 people. Result: The results of this study found that mothers who have good knowledge amounted to 55%, support moderate amounted to 50% and good families amounted to 50%, and application of EIBFas much as 55%. The results of this study explain that there is a significant relationship between the level of knowledge on the application of IMD (p-value = 0.002 and r = 0.495) and there is a significant relationship between family support for the application of IMD (p-value = 0,000 and r = 0.603)

Bioeconomics of the Philippine small pelagics fishery

Time series analysis of catch and effort data in the Philippines small pelagics fishery resulted in a level of biological and economic overexploitation. Open-access equilibrium has been reached at 410,000 hp representing a catch level of 465,000 tonnes. Present levels of effort would have to be reduced by 40% to attain maximum economic yield. An analysis of producer surplus showed that municipal aand commercial fishers were sustaining pure losses amounting to P9.4 billion indicating misallocation of labor and capital in an already overexploited fishery. Solutions to fisheries management problems are shown to emanate not just from the fishery, but more importantly, from the broader macroeconomic environment.Pelagic fisheries, Bioeconomics, Fishery economics, Fishery management, Philippines,

HAZARD ANALYSIS CRITICAL CONTROL POINT (HACCP) PADA USAHA JASABOGA DI KECAMATAN KOTAGEDE, KOTA YOGYAKARTA

Penelitian ini bertujuan untuk mengetahui hasil penerapan HACCP pada usaha jasaboga berupa titik kritis pada produksi ayam bacem dan mengetahui kualitas produk yang dihasilkan melalui uji cemaran fisik, kimia, dan mikrobiologis di Kecamatan Kotagede dan mengetahui hasil penerapan HACCP dengan mutu produk ayam bacem tersebut. Penelitian ini merupakan penelitian deskriptif dengan metode observasi langsung ke usaha jasaboga yang dilakukan pada tanggal 02 Februari – 29 Maret 2017. Lokasi usaha jasaboga ada di Kecamatan Kotagede dengan penentuan lokasi dilakukan secara purposive sampling dan pengambilan sampel ayam bacem secara random. Sampel ayam bacem diambil secara aseptik dan langsung dibawa ke laboratorium untuk dilakukan pemeriksaan kualitas mutu berdasarkan syarat fisik, kimia, dan mikrobiologis. Uji fisik yang dilakukan meliputi bau, rasa, warna, tekstur, dan keberadaan benda asing. Uji kimia meliputi pengukuran pH dan uji keberadaan Bahan Tambahan Makanan (BTM) Monosodium Glutamat (MSG), dan uji mikrobiologis yang dilakukan berupa uji Most Probable Number (MPN) Escherichia coli dan keberadaan Salmonella sp. Uji kualitas ayam bacem mengacu pada SNI 2897: 2008 dan permenkes RI No 715/MENKES/SK/V/2003 tentang persyaratan higiene sanitasi jasaboga. Hasil penelitian menunjukkan bahwa titik kritis pada pengolahan ayam bacem terletak pada proses pengolahan dengan alat yang tidak saniter, penjamah kurang higiene, dan sanitasi lingkungan yang kurang. Hasil HACCP pada kedua jasaboga tidak memenuhi standar permenkes RI No 715/MENKES/SK/V/2003, namun hasil uji fisik, kimia, dan mikrobiologisnya baik atau tidak ditemukan cemaran pada produk, sehingga ayam bacem pada usaha jasaboga di Kecamatan Kotagede, Kota Yogyakarta layak untuk dikonsumsi

Host searching behaviour of Diachasmimorpha kraussii (Fullaway) (Hymenoptera: Braconidae: Opiinae), a polyphagous parasitoid of Dacinae fruit flies (Diptera: Tephritidae)

Diachasmimorpha kraussii (Hymenoptera: Braconidae: Opiinae) is a koinobiont larval parasitoid of dacine fruit flies of the genus Bactrocera (Diptera: Tephritidae) in its native range (Australia, Papua New Guinea, Solomon Islands). The wasp is a potentially important control agent for pest fruit flies, having been considered for both classical and inundative biological control releases. I investigated the host searching, selection and utilisation mechanisms of the wasp against native host flies within its native range (Australia). Such studies are rare in opiine research where the majority of studies, because of the applied nature of the research, have been carried out using host flies and environments which are novel to the wasps. Diachasmimorpha kraussii oviposited equally into maggots of four fruit fly species, all of which coexist with the wasp in its native range (Australia), when tested in a choice trial using a uniform artificial diet media. While eggs laid into Bactrocera tryoni and B. jarvisi developed successfully through to adult wasps, eggs laid into B. cucumis and B. cacuminata were encapsulated. These results suggest that direct larval cues are not an important element in host selection by D. kraussii. Further exploring how D. kraussii locates suitable host larvae, I investigated the role of plant cues in host searching and selection. This was examined in a laboratory choice trial using uninfested fruit or fruit infested with either B. tryoni or B. jarvisi maggots. The results showed a consistent preference ranking among infested fruits by the wasp, with guava and peach most preferred, but with no response to uninfested fruits. Thus, it appears the wasp uses chemical cues emitted in response to fruit fly larval infestation for host location, but does not use cues from uninfested fruits. To further tease apart the role of (i) suitable and non-suitable maggots, (ii) infested and uninfested fruits of different plant species, and (iii) adult flies, in wasp host location and selection, I carried out a series of behavioural tests where I manipulated these attributes in a field cage. These trials confirmed that D. kraussii did not respond to cues in uninfested fruits, that there were consistent preferences by the wasps for different maggot infested fruits, that fruit preference did not vary depending on whether the maggots were physiologically suitable or not suitable for wasp offspring development, and finally, that adult flies appear to play a secondary role as indicators of larval infestation. To investigate wasp behaviour in an unrestrained environment, I concurrently observed diurnal foraging behaviours of both the wasp and one of its host fly in a small nectarine orchard. Wasp behaviour, both spatially and temporally, was not correlated with adult fruit fly behaviour or abundance. This study reinforced the point that infested fruit seems to be the primary cue used by foraging wasps. Wasp and fly feeding and mating was not observed in the orchard, implying these activities are occurring elsewhere. It is highly unlikely that these behaviours were happening within the orchard during the night as both insects are diurnal. As the final component of investigating host location, I carried out a habitat preference study for the wasp at the landscape scale. Using infested sentinel fruits, I tested the parasitism rate of B. tryoni in eucalyptus sclerophyll forest, rainforest and suburbia in South East Queensland. Although, rainforest is the likely endemic habitat of both B. tryoni and D. kraussii, B. tryoni abundance is significantly greater in suburban environments followed by eucalyptus sclerophyll forest. Parasitism rate was found to be higher in suburbia than in the eucalyptus sclerophyll forest, while no parasitism was recorded in the rainforest. This result suggests that wasps orient within the landscape towards areas of high host density and are not restricted by habitat types. Results from the different experiments suggest that host searching, selection and utilisation behaviour of D. kraussii are strongly influenced by cues associated with fruit fly larval feeding. Cues from uninfested fruits, the host larvae themselves, and the adult host flies play minimal roles. The discussion focuses on the fit of D. kraussii to Vinson’s classical parasitoid host location model and the implications of results for biological control, including recommendations for host and plant preference screening protocols and release regimes