6. Marco Teórico
6.2 Componentes de la Educación Financiera
6.2.5 Inversión
Figure 4-6(a) and 4-6(b) show a bright field microscopy image and the corresponding WEFS image with an objective of magnification 63x. Two regions were selected (frames in the bright field and the WEFS images) to evaluate the integrated intensity profile for single cells (right frame) and a colony (left frame) in Figure 4-6(a and b). The integrated intensity was calculated along the y-axis (height) and plotted as a function of distance (width). The intensity profiles for the colony and the single bacteria are depicted in Figure 4-6 (c) and (d), respectively.
Figure 4-6: (a) Bright field image (Objective: 63x, ZEISS LD Plan (b) corresponding WEFS image w
indicate two regions: colonized area (left) and only individual cells (right). The intensity profiles are from the WEFS image in 4.6 (b) where
intensity as a function of distance (x
As before, the scattering intensity of the colony region is significantly higher than that of the individual cell region. For the colony region, the intensity was very high and vari between 10,000 a.u and 15,500 a.u. along the entire distance axis (x
(c)). This is due to the fact that the colony has a large number of bacteria acting as scattering centers within a small region. Moreover, EPS present between bacter
contributed to the overall scattering intensity [39]. This plot also demonstrates a continuous intensity fluctuation for the bacteria in a colony present in the evanescence field. Inside the colonies, bacteria are obviously situated at slightly dif
(a) Bright field image (Objective: 63x, ZEISS LD Plan-NEOFLUAR) and (b) corresponding WEFS image with same magnification. The small white frames
indicate two regions: colonized area (left) and only individual cells (right). The s are from the WEFS image in 4.6 (b) where y-axis depicts integrated intensity as a function of distance (x-axis) for (c) colony and (d) individual cells. Scale
bars represent 10 µm.
As before, the scattering intensity of the colony region is significantly higher than that of the individual cell region. For the colony region, the intensity was very high and vari between 10,000 a.u and 15,500 a.u. along the entire distance axis (x-axis in Figure 4 (c)). This is due to the fact that the colony has a large number of bacteria acting as scattering centers within a small region. Moreover, EPS present between bacter
contributed to the overall scattering intensity [39]. This plot also demonstrates a continuous intensity fluctuation for the bacteria in a colony present in the evanescence field. Inside the colonies, bacteria are obviously situated at slightly dif
NEOFLUAR) and ith same magnification. The small white frames indicate two regions: colonized area (left) and only individual cells (right). The
axis depicts integrated xis) for (c) colony and (d) individual cells. Scale
As before, the scattering intensity of the colony region is significantly higher than that of the individual cell region. For the colony region, the intensity was very high and varied axis in Figure 4-6 (c)). This is due to the fact that the colony has a large number of bacteria acting as scattering centers within a small region. Moreover, EPS present between bacteria also contributed to the overall scattering intensity [39]. This plot also demonstrates a continuous intensity fluctuation for the bacteria in a colony present in the evanescence field. Inside the colonies, bacteria are obviously situated at slightly different distances
within the evanescence field. As a result, cells located at different depths of the evanescent field displayed different intensity values. Moreover, as the density of the bacteria is not homogeneous inside the colonies, the intensity distribution was also heterogeneous. All the colonies behaved in a similar manner.
Figure 4-6(d) shows the intensity profile of the individual bacteria within the region on the right side of the image. There were three distinct peaks ranging from 1500 a.u to 3500 a.u. and some fluctuations in intensity which was less than 700 a.u. Fluctuations below 500 a.u was considered as background noise which might arise because of the presence of some EPS or some randomly scattered photons. There were some values in the distance axis where almost no scattering intensity was present. The three peaks located approximately at 2.5, 5 and 12 mm distances in Figure 3(d) confirmed the attachment of three bacterial cells to waveguide surface. The presence of three bacterial cells can be visualized clearly from the left frame in Figure 4-6(a). It was not possible to interpret why the micrometer-sized bacterial cells which are one order of magnitude larger that the penetration depth of the evanescence field, produced scattering intensities on a comparable scattering-spot size. There can be many possible causes for the different peak heights, for example different bacteria heights, presence of more EPS, orientation of the cells on the surface etc. All three peaks were produced by individual bacterial cells. Hence, one of the reasons for the highest scattering peak may be because this rod-shaped bacterium was attached to the surface with its longer axis parallel to the waveguide surface occupying a larger scattering volume. On the other hand, the other two bacteria were attached perpendicularly with one of their poles occupying less scattering volume on the waveguide surface. It was unclear if the bacteria had secreted EPS as it can also be a source of scattering intensity. In order to find a solid interpretation for the intensity difference and attachment quality, a thorough theoretical investigation including size, shape, orientation, distance from surface, presence of EPS as well as the precise location of the cells is necessary.