The impact of trade promotion services on Canadian exporter performance.

We evaluate the impact of the export promotion program delivered by the Canadian Trade Commissioner Service on various dimensions of export performance. Over the 1999-2006 time period we study, Canadian firms successfully diversified their exports to destinations beyond the United States and smaller firms increased their share of total exports. Both of these achievements are explicit aims of the program, but in order to make causal inferences we rely on various identifying assumptions from the treatment effects literature. The results indicate very robustly that the program had an effect at the intensive margin, boosting the average level of exports to given product-destination markets. Effects at the extensive margins of trade, increasing the number of export destinations or number of products exported, are smaller and more sensitive to the identification assumption. This finding differs from previous studies for several Latin American countries where extensive margin effects were most robust. One reason is that the Canadian program was most effective for larger firms and for firms already active on several export markets.

The impact of trade promotion services on Canadian exporter performance.

We evaluate the impact of the programs delivered by the Canadian Trade Commissioner Service (TCS) on export performance by Canadian firms. We draw on a unique set of microdata created by linking three separate firm-level databases: Statistics Canada’s Exporter Register and its Business Register, which provide information on export activity and firm characteristics, and the TCS client management database maintained by Foreign Affairs and International Trade Canada, which contains details on trade promotion services provided to Canadian firms. We apply the treatment effects analytical framework to isolate the effects of public sector trade promotion. We find that TCS programs have a consistent and positive impact on Canadian exporter performance. Exporters that access TCS services export, on average, 17.9 percent more than comparable exporters that do not. Furthermore, we also find that TCS assistance benefits exporters in terms of product and market diversification.

Novel sesquiterpene lactone analogues as potent anti-breast cancer agents

Triple-negative breast cancer (TNBC) is associated with high grade, metastatic phenotype, younger patient age, and poor prognosis. The discovery of an effective anti-TNBC agent has been a challenge in oncology. In this study, fifty-eight ester derivatives (DETDs) with a novel sesquiterpene dilactone skeleton were organically synthesized from a bioactive natural product deoxyelephantopin (DET). Among them, DETD-35 showed potent antiproliferative activities against a panel of breast cancer cell lines including TNBC cell line MDA-MB-231, without inhibiting normal mammary cells M10. DETD-35 exhibited a better effect than parental DET on inhibiting migration, invasion, and motility of MDA-MB-231 cells in a concentration-dependent manner. Comparative study of DETD-35, DET and chemotherapeutic drug paclitaxel (PTX) showed that PTX mainly caused a typical time-dependent G2/M cell-cycle arrest, while DETD-35 or DET treatment induced cell apoptosis. In vivo efficacy of DETD-35 was evaluated using a lung metastatic MDA-MB-231 xenograft mouse model. DETD-35 significantly suppressed metastatic pulmonary foci information along with the expression level of VEGF and COX-2 in SCID mice. DETD-35 also showed a synergistic antitumor effect with PTX and . This study suggests that the novel compound DETD-35 may have a potential to be further developed into a therapeutic or adjuvant agent for chemotherapy against metastatic TNBC

Dynamical Decoupling of Qubits in Spin Bath under Periodic Quantum Control

We investigate the feasibility for the preservation of coherence and entanglement of one and two spin qubits coupled to an interacting quantum spin-1/2 chain within the dynamical decoupling (DD) scheme. The performance is examined by counting number of computing pulses that can be applied periodically with period of $T$ before qubits become decoherent, while identical decoupling pulse sequence is applied within each cycle. By considering pulses with mixed directions and finite width controlled by magnetic fields, it is shown that pulse-width accumulation degrades the performance of sequences with larger number of pulses and feasible magnetic fields in practice restrict the consideration to sequences with number of decoupling pulses being less than 10 within each cycle. Furthermore, within each cycle $T$, exact nontrivial pulse sequences are found for the first time to suppress the qubit-bath coupling to $O(T^{N+1})$ progressively with minimum number of pulses being $4,7,12$ for $N=1,2,3$. These sequences, when applied to all qubits, are shown to preserve both the entanglement and coherence. Based on time-dependent density matrix renormalization, our numerical results show that for modest magnetic fields (10-40 Tesla) available in laboratories, the overall performance is optimized when number of pulses in each cycle is 4 or 7 with pulse directions be alternating between x and z. Our results provide useful guides for the preservation of coherence and entanglement of spin qubits in solid state.Comment: 11 pages, 9 figure

Differential Gene Expression in Response to Papayaringspot virus Infection in Cucumis metuliferus UsingcDNA- Amplified Fragment Length PolymorphismAnalysis

A better understanding of virus resistance mechanisms can offer more effective strategies to control virus diseases. Papayaringspot virus (PRSV), Potyviridae, causes severe economical losses in papaya and cucurbit production worldwide. However,no resistance gene against PRSV has been identified to date. This study aimed to identify candidate PRSV resistance genesusing cDNA-AFLP analysis and offered an open architecture and transcriptomic method to study those transcriptsdifferentially expressed after virus inoculation. The whole genome expression profile of Cucumis metuliferus inoculated withPRSV was generated using cDNA-amplified fragment length polymorphism (cDNA-AFLP) method. Transcript derivedfragments (TDFs) identified from the resistant line PI 292190 may represent genes involved in the mechanism of PRSVresistance. C. metuliferus susceptible Acc. 2459 and resistant PI 292190 lines were inoculated with PRSV and subsequentlytotal RNA was isolated for cDNA-AFLP analysis. More than 400 TDFs were expressed specifically in resistant line PI 292190. Atotal of 116 TDFs were cloned and their expression patterns and putative functions in the PRSV-resistance mechanism werefurther characterized. Subsequently, 28 out of 116 candidates which showed two-fold higher expression levels in resistant PI292190 than those in susceptible Acc. 2459 after virus inoculation were selected from the reverse northern blot andbioinformatic analysis. Furthermore, the time point expression profiles of these candidates by northern blot analysissuggested that they might play roles in resistance against PRSV and could potentially provide valuable information forcontrolling PRSV disease in the future