The Cry insecticidal proteins of Bacillus thuringiensis (Bt) are produced by transgenic crops for effective and environmentally-safe insect pest control. These transgenic Bt crops are considered to be the most successful agricultural biotechnology for insect control, yet their sustainability is threatened by the evolution of resistance in targeted pests. The evidence suggests that this resistance is probably due to the alterations in recognition of Cry toxin receptors in the insect midgut membrane. Consequently, information is needed on determinants of receptor recognition for designing improved toxins and to adopt effective insect resistance management practices. In this study four Cry proteins, Cry1Ac, Cry2Ac7, Cry1Fa and Cry1Ie2 were expressed either in E. coli expression system or in native Bt strain. Insoluble Cry1Ac and Cry2Ac7 proteins were refolded and purified prior to use. Bioassays of Cry1Ac (C-terminally truncated version) and Cry2Ac7 protoxins were performed with an armyworm, Spodoptera litura Fabricius (Lepidoptera: Noctuidae), a polyphagous cosmopolitan insect which is a serious crop pest of many Asian countries including Pakistan. Cry2Ac7 was found to be toxic to this pest whereas tnCry1ac (truncated Cry1Ac) was nontoxic. To activate the protoxins, the proteins were trypsin digested and further purified by anion-exchange chromatography. Trypsin activated proteins (toxins) were assayed against velvetbean caterpillar, Anticarsia gemmatalis and soybean looper, Chrysodeixes includens (Pseudoplusia includens) which are lepidopteran pests of crops of great economic importance especially soybean. All these proteins were found to be toxic to both of these pests. Amongst all these toxins Cry1Ac was the most highly toxic protein. In general, C. includens larvae were always less susceptible compared to larvae of A. gemmatalis to these toxins which is in agreement with the previous findings of the relative susceptibilities of these soybean pests for Bt pesticides. The Bt insecticidal proteins Cry1Ac and Cry2Ac7 belong to the three domain family of Bt toxins. Commercial transgenic soybean hybrids produce Cry1Ac to control larvae of the soybean looper and the velvetbean caterpillar. Specificity of Cry proteins is known to be majorly determined by domain II and domain III of the toxin. In this study, we constructed a hybrid toxin (H1.2Ac) containing domains I and II of Cry1Ac and domain III of Cry2Ac7, in an attempt to obtain a protein with enhanced toxicity compared to parent toxins. H1.2Ac protein was expressed in E. coli expression system and was refolded and purified using Histagged chromatography. Recombinant H1.2Ac protein was also trypsin activated prior to the bioassays. Bioassays with H1.2Ac revealed toxicity to larvae of A. gemmatalis but not to C. includens. Saturation binding assays with radiolabeled toxins and midgut brush border membrane vesicles demonstrated no specific H1.2Ac binding to C. includens, while binding to A. gemmatalis was specific and saturable. The competition binding assays showed that Cry1Ac specificity against A. gemmatalis was mainly dictated by domain II. The binding assay in the presence of N-acetylgalactosamine (GalNAc) further clarifies the significance of domain III of Cry1Ac in binding to the receptors of C. includens. Taken together, these distinct interactions with binding sites explain the differential susceptibility of C. includens and A. gemmatalis to Cry1Ac and may provide guidelines for designing the improved toxins against soybean pests. The significance of this work is in identifying Cry2Ac7 as toxic to S. litura and Cry1Ac, Cry2Ac7, Cry1Fa and Cry1Ie2 as toxic to C. includens and A. gemmatalis. Cry1Ie2 can be pyramided with any or all of Cry1Ac, Cry2Ac7 and Cry1Fa proteins in transgenic plants to enhance their efficiency to combat insect pests. While the present study presents evidence for the importance of Cry1Ac domain III for toxicity against C. includens, further research would be needed to identify lethal Cry1Ac receptors and determine their interactions with domains II and/or III of Cry1Ac. This information contributes to the design of more active insecticidal proteins against this pest and our general understanding of the Cry mode of action in Lepidoptera.
تقریظ ِ دوئم زیرِ نظر کتاب’’نسیم سخن‘‘ نظروں سے گزری ۔یہ ایک مجموعہ تقریر ہے اور خدمتِ خلق کے جذبہ کے تحت اس کو مدون کیا گیا ہے۔ اس میں طلبا و طالبات کی ضروریات کو خصوصی طور پر پیشِ نظر رکھا گیا ہے۔ طلبا کے لیے ترغیبی انداز اختیار کیا گیا ہے۔ تقاریر میں اختصار اور جامعیت کو ملحوظِ خاطر رکھا گیا ہے۔ گزشتہ ادوار میں مقابلہ جات میں متعدد مرتبہ پوزیشنیں حاصل کرنے والا حافظ محمد اکرم راشدؔ کا یہ مجموعہ تقاریر ’’نسیم سخن‘‘ آئندہ بھی ضرور کفایت کرے گا۔ اس میں موجود مواد تشنگانِ علم کی پیاس بجھانے میں ممد و معاون ثابت ہو گا۔ ایک جگہ پر اتنی تقاریر کا مل جانا ناممکن نہیں تو محال ضرور ہے۔ حافظ محمد اکرم راشدؔ سے میرا دیرینہ تعلق ہے۔ یہ ایک علم دوست انسان ہیں۔ خاندانی شرافت اور علم کی بہاریں انھیں ورثے میں ملی ہیں۔ان کی طبع میں حلم و بردباری ہے۔ اپنی تمام تر خصوصیات کو عوام الناس میں بالعموم اور طلبا میں بالخصوص منتقل کرنے کا جذبہ رکھتے ہیں۔ یہ دینی علوم کا حظِ وافر رکھنے کے ساتھ ساتھ ایم۔اے، ایم۔ایڈ بھی ہیں اور ایم۔اے عربی میں گولڈ میڈلسٹ بھی ہیں۔آپ ایک گورنمنٹ ہائی سکول سے بطور رئیس مدرسہ ریٹائر ہوئے ہیں۔ فی الوقت جامع مسجد این۔ بلاک عارف والا میں بطور خطیب فرائض سر انجام دے رہے ہیں۔ عارف والا اوراس کے مضافات میں بطور خوش نویس بھی ان کی شناخت ہے۔قبل از ایں ’’نگارشاتِ راشد‘‘ کے نام سے مختلف مضامین و مقالات پر مشتمل ان کی کتاب زیورِ طباعت سے آراستہ ہو کر منظرِ عام پر آچکی ہے۔اللہ تعالیٰ ان کی اس کد وکاوش کو قبول فرمائے۔ رانا کوثر خاں چیف ایکزیکٹو آفیسر(ایجوکیشن) ڈسٹرکٹ ایجوکیشن اتھارٹی ، پاک پتن
The personality of Allama Iqbal is the integral part of the religious and national thinking of the Muslims of subcontinent, and for Pakistanis along with a religious thinker he is also the person who gave the idea of Pakistan. Because of this legacy Iqbal is considered as the founder of a school of thought in Pakistan's academic atmosphere. The magnitude of this position and importance is evident from the fact that the people of different intellectual backgrounds and ideologies have been seeking evidence from Iqbal in support of their arguments. So even the proponents of socialist ideology or the holders of the thought of negating the legal status of Hadeeth have tried to prove Iqbal as a torch bearer of their stance and saw their struggle as a continuation of his (Iqbal’s) thinking. But it is a general rule that a person, especially the one who is a prominent figure and there are a lot of themes that are present in his thoughts, cannot be judged on the basis of only some of his works. So declaring Iqbal as the negator of legal status of the Hadeeth because of some of his writings is not a fair academic activity. This paper would study the actual view of Iqbal about the legal status of Sunnah as well the place of Prophethood in his thoughts and try to figure out whether his stand in this regard is in accordance with the traditional concept o1r it is different and if it is different then how much is it different?
Organizational culture has a definite impact on organizational performance and employee’s performance to
become important within the system. This study shows the dimensions of culture (power distance, masculinity
& femininity) and evaluates its impact on perceived organizational performance.
A sample of 200 respondents working in 10 different organizations was selected. Questionnaires sent directly
to the target population had four parts. In the first part there were 5 questions related to personal profile , 4
questions were there in second part related to power distance , 5 questions related to masculinity &
femininity ,10 questions related to perceived organizational performance , and 8 questions pertaining to
employees performance which was use as mediating variable.
The study shows that cultural dimensions like power distance has —ve impact and masculinity & femininity
has +ve impact on employee’s performance as well as perceived organizational performance. Mediation
regression analysis proved mediation between culture and perceived organizational performance.