Tandem-running

In these cases, orientation of scouts is probably achieved without the use of pheromones. However, recruitment by tandem-running in Camponotus sericeus is guided by an orientation trail previously laid by scouts from their hind-guts (HOlldobler et al., 1974). 

HOlldobler, B. and Traniello, J. (1980b) Tandem running pheromone in ponerine ants. Naturwissenschaften, 67, 360. 

Fig. 16.16 Post-flight behavior of Trinervitermes bettonianus. (a) Female calling behavior, showing tergal glands and sternal gland exposed (b) Male following strong pheromone trail of female (c) Tandem run, with male in attennal contact with female (after Leuthold, 1975).

Sampling saturated reservoirs with this technique requires special care to attempt to obtain a representative sample, and in any case when the flowing bottom hole pressure is lower than the bubble point, the validity of the sample remains doubtful. Multiple subsurface samples are usually taken by running sample bombs in tandem or performing repeat runs. The samples are checked for consistency by measuring their bubble point pressure at surface temperature. Samples whose bubble point lie within 2% of each other may be sent to the laboratory for PVT analysis. 

In practice, it is found that this simple implementation is not the most effective approach. There are two particular problems. First, when the two simulations are run in tandem then significant correlations can arise, which results in large systematic errors. There are a number of ways to avoid these correlations, such as moving the J-walker an extra nuniher... 

Indol-3-ylcarbinols can also be reduced using Et3SiH-TFA. Aryl indolyl-3-ylcarbinols can be formed in situ from 2-alkylindoles and benzaldehydes. These reactions, when run in tandem, provide a versatile route to 3-benzylin-doles[l 1]. Indole itself undergoes reduction to indoline under these conditions. lndol-3-ylcarbinols can also be generated by organomelallic additions to 3-acylindoles[12]. 

An AutoSpec-TOF mass spectrometer has a magnetic sector and an electron multiplier ion detector for carrying out one type of mass spectrometry plus a TOF analyzer with a microchannel plate multipoint ion collector for another type of mass spectrometry. Either analyzer can be used separately, or the two can be run in tandem (Figure 20.4). 

An interesting one-pot hydroformylation/Fischer indole sequence can be achieved by running the hydroformylation in the presence of a phenylhy-drazine. This protocol gave access to the methyl ester of the plant growth regulator 3-indole butanoic acid (IBA) (Scheme 16) [61-63]. A review on related tandem processes involving the hydroformylation as a key step has appeared recently [9]. 

There exist essentially three categories of SCX/RP/MS/MS approaches. In one approach, SCX is run off-line followed by on-line RP/MS/MS (Fig. 11.1). In the offline SCX approach, fractions do not directly elute onto RP material but rather are collected. In one of the two in-line approaches, SCX is run in line with RP/MS/MS using different columns for SCX and RP (Fig. 11.2). In the multidimensional protein identification technology approach (MudPIT), SCX and RP are run in line in the same column, and this column serves as the ion source for a tandem mass spectrometer (Fig. 11.3). Both the in-line approaches are true SCX/RP/MS/MS approaches the first approach could be abbreviated as SCX—RP/MS/MS where... 

Using the Tomtec Quadra 96 workstation, 0.1 mL of the ethyl acetate layer was transferred to a 96-well collection plate containing 0.4 mL of acetonitrile in each sample well. The solution was mixed 10 times by aspiration and dispersion on the Tomtec. The plate was then covered with a sealing mat and stored at 2 to 8°C until LC/MS/MS analysis. The HILIC-MS/MS system consisted of a Shimadzu 10ADVP HPLC system and Perkin Elmer Sciex API 3000 and 4000 tandem mass spectrometers operating in the positive ESI mode. The analytical column was Betasil silica (5 fim, 50 x 3 mm) and a mobile phase of acetonitrile water formic acid with a linear gradient elution from 95 5 0.1 to 73.5 26.5 0.1 was used for 2 min. The flow rate was 1.0 mL/min for the API 3000 and 1.5 mL/min for the API 4000 without any eluent split. The injection volume was 10 jjL and a run time of 2.75 min was employed. 

The secondary extruder is typically larger in diameter than the primary machine, and it rotates at a lower screw speed. For example, a midsized tandem line would be constructed using a 114.3 mm diameter primary extruder and a 152.4 mm secondary extruder. The primary extruder would operate at a normal screw speed (50 to 70 rpm) and could generate the pressure required to run the downstream equipment. The secondary extruder would operate at a lower screw speed (10 to 15 rpm) so that the entry and exit pressure for the extruder are about the same. 

Earlier attempts to use the AFM for mechanically stretching chromatin fibers have run into a rather unexpected artifact. Long native chromatin fibers isolated from chicken erythrocytes, or fibers assembled in vitro from purified histones and relatively short, tandemly repeated DNA sequences were deposited on mica or glass surfaces and pulled with the AFM tip [69,70]. In such stretching experiments the scanning of the sample in the x- and y-direction used for imaging was disabled, and the cantilever-mounted tip was allowed to move only in the z-direction, i.e., upwards and downwards, away and towards the surface. When the AFM tip is pushed into the sample, it may attach to the sample by non-specific adsorption upon retraction it stretches the sample and force-extension curves are recorded (see Fig. lb for an explanation of a typical force curve). 

Table 2.1.3 Multiple reaction monitoring of amino acids for their tandem mass spectrometry quantitation. In daily practise not all mentioned amino acids are measured in one run, but a set of ten dedicated evaluation programs has been developed, covering groups of amino acids associated with groups of disorders. Amino acids presented in italics indicate stable-isotope-labeled internal standards ... 

Run spectrum in photometer from 380 nm to 600 nm, using tandem cuvettes . Put 1 ml of solution A into one chamber and 1 ml of solution B into the other chamber of each of two tandem cuvettes ... 

Liquid chromatography (Waters, Alliance 2695 pump, Milford, MA, USA) is performed using a prevail carbohydrates ES 54 column (250x4.6 mm, bead size 5 pm, Alltech). An isocratic eluent of 50% acetonitrile/water is used, with the column kept at room temperature. The flow rate is set to 1 ml/min and is split after the analytical column in a ratio of 1 5, resulting in an inlet flow into the tandem mass spectrometer of 200 pl/min 10 pi of sample is injected onto the column and the total run time is 6 min. 

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